Preparation method and application of Al2O3-Al composite packaging material

Abstract

The present invention discloses a preparation method and use of an Al2O3-Al composite packaging material, and the preparation method comprises the following steps: step A: uniformly mixing aluminum powder, aluminum oxide powder, CuO-TiO2 powder and ceramic particle additive powder to obtain a mixed raw material A; step B: adding a polyvinyl alcohol aqueous solution to the mixed raw material A and grinding it fully to obtain a mixed raw material B; step C: placing the mixed raw material B in a ball mill for ball milling, and obtaining a mixed raw material C after the ball milling is completed; step D: cold-pressing the mixed raw material C to obtain a prefabricated block; step E: placing the prefabricated block in a resistance furnace for sintering, and cooling it to room temperature with the furnace after the sintering is completed, to obtain an Al2O3-Al composite packaging material. The composite packaging material is used to encapsulate an aluminum-silicon alloy phase change heat storage material. The composite packaging material prepared by the present invention can be used to encapsulate an aluminum-silicon alloy phase change heat storage material, and has the advantages of good corrosion resistance and not easy to leak.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon-aluminum alloy phase change material packaging. 2 O 3 -Preparation method and application of Al composite packaging material. Background Art

[0002] Aluminum-based alloy phase change heat storage materials will have a melting-solidification cycle during operation due to their service conditions, and liquid aluminum alloys at high temperatures are extremely corrosive and easily react chemically with general container materials. Aluminum elements react easily with most metals at high temperatures, and the resulting reactants are all eutectic alloys, and the melting points of eutectic alloys are relatively low. This results in even heat-resistant and corrosion-resistant alloys being selectively corroded by aluminum liquid at high temperatures. In order to avoid leakage of heat storage materials caused by corrosion penetration of container materials, container materials should be selected from materials with mature processes and stable performance. Although ceramic materials have good resistance to high-temperature aluminum liquid, the thermal conductivity of ceramic materials is generally low, which also limits their application in the field of solar thermal energy. In addition, when Al powder and Al-Si alloy powder are coated with ceramics to prepare heat storage materials, the thermal stress generated by the volume expansion during the solid-liquid phase transition process can easily cause the coated brittle ceramic shell to rupture, resulting in leakage of heat storage materials. At the same time, ceramic Al 2 O 3 The shell has poor thermal conductivity, which is not conducive to the subsequent transmission of heat storage. In order to improve the corrosion resistance of heat storage material containers at high temperatures, scholars have conducted a lot of research. People first studied stainless steel. The addition of alloy elements greatly improved the corrosion resistance of stainless steel; however, the Fe element in stainless steel will react with the Al element in the heat storage material to generate an Al-Fe eutectic alloy with a lower melting point; this will not only reduce the heat storage capacity of the heat storage material, but also cause the container material to be gradually corroded, resulting in leakage of the heat storage material. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide an Al 2 O 3 The invention discloses a preparation method and application of an Al-Si composite packaging material, so as to solve the problems that the existing packaging materials have poor corrosion resistance and low thermal conductivity when packaging Al-Si alloy phase change materials, or the packaging materials may leak due to brittle cracking caused by volume expansion during the phase change process.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A kind of Al 2 O 3 -Al composite packaging material preparation method, characterized in that it comprises the following steps:

[0006] Step A: Aluminum powder, alumina powder, CuO-TiO 2 The powder and the ceramic particle additive powder are mixed evenly to obtain a mixed raw material A; step B: adding a polyvinyl alcohol aqueous solution to the mixed raw material A and grinding it fully to obtain a mixed raw material B; step C: placing the mixed raw material B in a ball mill for ball milling, and after the ball milling is completed, a mixed raw material C is obtained; step D: cold-pressing the mixed raw material C to obtain a prefabricated block; step E: placing the prefabricated block in a resistance furnace for sintering, and cooling it to room temperature with the furnace after the sintering is completed, so as to obtain Al 2 O 3 -Al composite packaging materials.

[0007] A kind of Al 2 O 3 -Al composite packaging material, characterized in that the above-mentioned Al 2 O 3 -Al composite packaging materials are used to encapsulate aluminum-silicon alloy phase change heat storage materials.

[0008] The technical solution of the present invention achieves the following beneficial technical effects:

[0009] The present invention is used to prepare Al 2 O 3 -Al composite packaging materials with SiC or AlN ceramic particle additives and CuO-TiO 2 Sintering aids, and by controlling the raw material ratio and process parameters, a porosity of about 27%, a bending strength greater than 40MPa, a thermal conductivity of 13.48W / mK, and a latent heat of 179.58J / g were prepared. 2 O 3 -Al composite packaging material, which has high compatibility with aluminum-silicon alloy phase change heat storage materials, especially with Al-12Si-0.02wt%Sr alloy, can be used to encapsulate aluminum-silicon alloy phase change heat storage materials, and has the advantages of good corrosion resistance, not easy to leak, and low thermal conductivity of aluminum-silicon alloy phase change heat storage materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Experimental process flow chart of an embodiment of the present invention;

[0011] Figure 2a , Figure 2b , Figure 2c and Figure 2d In the embodiment of the present invention, the SiC content is 0.5wt%, the pressing pressure is 100MPa and the Al 2 O 3When the ratio of Al / Al is 50:50, the Al prepared by sintering at 750℃ for 2h, 850℃ for 2h, 850℃ for 1.5h and 800℃ for 2h 2 O 3 Macroscopic morphology of / Al composites;

[0012] Figure 3a and Figure 3b In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and Al 2 O 3 When the ratio of / Al is 50:50, the Al 2 O 3 Two macroscopic morphology images of / Al composites; Figure 3c and Figure 3d In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and Al 2 O 3 When the ratio of / Al is 50:50, the Al 2 O 3 Two macroscopic morphology images of / Al composites; Figure 3e and Figure 3f In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and Al 2 O 3 When the ratio of / Al is 50:50, the Al 2 O 3 Two macroscopic morphology images of / Al composites;

[0013] Figure 4a , Figure 4b , Figure 4c , Figure 4d and Figure 4e In the embodiment of the present invention, when the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and the pressing pressure is 300MPa, Al 2 O 3 The Al prepared when the ratio of Al / Al was 35:65, 40:60, 45:55, 50:50 and 55:45 respectively 2 O 3 Macroscopic morphology of / Al composites;

[0014] Figure 5a , Figure 5b and Figure 5c In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and the pressing pressure is 300MPa, and the CuO-TiO2 When the addition amount of sintering aid is 2wt%, Al 2 O 3 The Al prepared with the ratio of / Al being 40:60, 35:65 and 30:70 respectively 2 O 3 Macroscopic morphology of / Al composites;

[0015] Figure 6a and Figure 6b In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h, the pressing pressure is 300MPa and the Al 2 O 3 When the ratio of CuO-TiO / Al is 35:65, 2 The Al2O3 prepared by adding 0 and 2 wt% sintering aids 2 O 3 SEM images of / Al composites;

[0016] Figure 7a and Figure 7b In the embodiment of the present invention, when the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning EDS spectrum of / Al composite materials and distribution spectrum of O element in surface scanning EDS;

[0017] Figure 7c and Figure 7d In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and the pressing pressure is 300MPa, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt%, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning EDS spectrum of / Al composite materials and distribution spectrum of O element in surface scanning EDS;

[0018] Figure 8a and Figure 8b In the embodiment of the present invention, when the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Al in / Al composites3 Ti morphology spectrum and Al 3 EDS spectrum of point A in the Ti morphology image;

[0019] Figure 9a and Figure 9b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the / Al ratio is 35:65, the Al 2 O 3 Effect curve of porosity and flexural strength of / Al composites;

[0020] Fig.10a , Fig.10b , Fig.10c and Fig.10d The sintering conditions in the embodiment of the present invention are 800°C for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the SiC content is 0wt%, 0.5wt%, 1wt% and 1.5wt%, the Al2O3 prepared under different pressing pressures (the pressure from left to right is 100Mpa, 200Mpa, 300Mpa) is 2 O 3 / Al composite cross-sectional morphology;

[0021] Fig.11a , Fig.11b , Fig.11c , Fig.11d and Fig.11e In the embodiment of the present invention, the SiC content is 0.5wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (50μm), surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and Si element distribution map in surface scanning EDS (30μm) of the Si / Al composite material;

[0022] Fig.12a , Figure 12b , Fig.12c , Fig.12d and Fig.12e In the embodiment of the present invention, the SiC content is 1wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (50μm), surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and Si element distribution map in surface scanning EDS (30μm) of the Si / Al composite material;

[0023] Fig.13a , Fig.13b , Fig.13c , Fig.13d and Fig.13e In the embodiment of the present invention, the SiC content is 1.5wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (50μm), surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and Si element distribution map in surface scanning EDS (30μm) of the Si / Al composite material;

[0024] Fig.14a and Fig.14b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the / Al ratio is 35:65, the Al 2 O 3 Effect curves of thermal conductivity and latent heat of / Al composite materials;

[0025] Fig.15a and Fig.15b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O3 When the SiC / Al ratio is 40:60, the Al 2 O 3 Effect curve of porosity and flexural strength of / Al composites;

[0026] Fig.16a and Fig.16b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the SiC / Al ratio is 40:60, the Al 2 O 3 Effect curves of thermal conductivity and latent heat of / Al composite materials;

[0027] Fig.17a and Fig.17b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the / Al ratio is 35:65, the AlN prepared under different AlN contents and different pressing pressures 2 O 3 Effect curve of porosity and flexural strength of / Al composites;

[0028] Fig.18a , Fig.18b , Fig.18c and Fig.18d The sintering conditions in the embodiment of the present invention are 800°C for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the ratio of Al / Al is 35:65, the AlN contents are 0wt%, 0.5wt%, 1wt% and 1.5wt%, respectively, and the AlN prepared under different pressing pressures (the pressure from left to right is 100Mpa, 200Mpa, 300Mpa, respectively) 2 O 3 / Al composite cross-sectional morphology;

[0029] Fig.19a , Fig.19b , Fig.19c and Fig.19d In the embodiment of the present invention, the AlN content is 0.5wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and N element distribution map in surface scanning EDS (30μm) of the Mg / Al composite material;

[0030] Fig.20a , Fig.20b , Fig.20c and Fig.20d In the embodiment of the present invention, the AlN content is 1.0wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and N element distribution map in surface scanning EDS (30μm) of the Mg / Al composite material;

[0031] Fig.21a , Figure 21b , Fig.21c and Fig.21d In the embodiment of the present invention, the AlN content is 1.5wt%, the sintering conditions are 800℃ for 2h, and the CuO-TiO 2 When the addition amount of sintering aid is 2wt% and the pressing pressure is 300MPa, Al 2 O 3 The Al / Al ratio was 35:65. 2 O 3 Surface scanning microstructure map (30μm), Al element distribution map in surface scanning EDS (30μm), O element distribution map in surface scanning EDS (30μm) and N element distribution map in surface scanning EDS (30μm) of the Mg / Al composite material;

[0032] Fig.22a and Figure 22b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3When the / Al ratio is 35:65, the AlN prepared under different AlN contents and different pressing pressures 2 O 3 Effect curves of thermal conductivity and latent heat of / Al composite materials;

[0033] Fig.23a and Figure 23b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the ratio of Al / Al is 40:60, the AlN prepared under different AlN contents and different pressing pressures 2 O 3 Effect curve of porosity and flexural strength of / Al composites;

[0034] Fig.24a and Figure 24b The sintering conditions in the embodiment of the present invention are 800℃ for 2h, CuO-TiO 2 The addition amount of sintering aid is 2wt% and Al 2 O 3 When the ratio of Al / Al is 40:60, the AlN prepared under different AlN contents and different pressing pressures 2 O 3 Effect curves of thermal conductivity and latent heat of / Al composite materials;

[0035] Fig.25a , Fig.25b , Fig.25c , Fig.25d and Fig.25e In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 hours, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of SiC to Al is 35:65 and the SiC content is 1wt%, the Al 2 O 3 SEM images of the alloy interfaces of / Al composites with Al-12Si-0wt%Sr, Al-12Si-0.01wt%Sr, Al-12Si-0.02wt%Sr, Al-12Si-0.03wt%Sr and Al-12Si-0.04wt%Sr, respectively;

[0036] Fig.26a , Figure 26b , Fig.26c and Fig.26dIn the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 35:65 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm) and Si element distribution spectrum in EDS spectrum (500μm);

[0037] Fig.27a , Figure 27b , Fig.27c and Fig.27d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 35:65 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.01wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm) and Si element distribution spectrum in EDS spectrum (500μm);

[0038] Fig.28a , Fig.28b , Fig.28c , Fig.28d and Fig.28e In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 35:65 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.02wt%Sr alloy interface EDS spectrum, C element distribution spectrum in EDS spectrum (500μm), O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm) and Si element distribution spectrum in EDS spectrum (500μm);

[0039] Fig.29a , Fig.29b , Fig.29c and Fig.29d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 35:65 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.03wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm) and Si element distribution spectrum in EDS spectrum (500μm);

[0040] Fig.30a , Fig.30b , Fig.30c and Fig.30d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 35:65 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.04wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm) and Si element distribution spectrum in EDS spectrum (500μm);

[0041] Fig.31a , Fig.31b , Fig.31c , Fig.31d and Fig.31e In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 hours, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al 2 O 3SEM images of interfaces between / Al composite materials and Al-12Si-0wt%Sr, Al-12Si-0.01wt%Sr, Al-12Si-0.02wt%Sr, Al-12Si-0.03wt%Sr and Al-12Si-0.04wt%Sr alloys, respectively;

[0042] Fig.32a , Figure 32b , Fig.32c and Fig.32d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0043] Fig.33a , Figure 33b , Fig.33c and Fig.33d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.01wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0044] Fig.34a , Fig.34b , Fig.34c and Fig.34d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al2 O 3 / Al composite material and Al-12Si-0.02wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0045] Fig.35a , Fig.35b , Fig.35c and Fig.35d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.03wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0046] Fig.36a , Fig.36b , Fig.36c and Fig.36d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / SiC is 40:60 and the SiC content is 1wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.04wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0047] Fig.37a , Figure 37b , Fig.37c , Fig.37d and Fig.37e In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 hours, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O3 When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 SEM images of interfaces between / Al composite materials and Al-12Si-0wt%Sr, Al-12Si-0.01wt%Sr, Al-12Si-0.02wt%Sr, Al-12Si-0.03wt%Sr and Al-12Si-0.04wt%Sr alloys, respectively;

[0048] Fig.38a , Figure 38b , Fig.38c and Fig.38d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0049] Fig.39a , Fig.39b , Fig.39c and Fig.39d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.01wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0050] Fig.40a , Fig.40b , Fig.40c and Fig.40d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2The addition amount of sintering aid is 2wt%, Al 2 O 3 When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.02wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0051] Fig.41a , Fig.41b , Fig.41c and Fig.41d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.03wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0052] Fig.42a , Figure 42b , Fig.42c and Fig.42d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.04wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0053] Fig.43a , Figure 43b , Fig.43c , Figure 43d and Figure 43eIn the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 hours, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 SEM images of interfaces between / Al composite materials and Al-12Si-0wt%Sr, Al-12Si-0.01wt%Sr, Al-12Si-0.02wt%Sr, Al-12Si-0.03wt%Sr and Al-12Si-0.04wt%Sr alloys, respectively;

[0054] Fig.44a , Figure 44b , Fig.44c and Fig.44d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0055] Fig.45a , Fig.45b , Fig.45c and Fig.45d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800°C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.01wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0056] Fig.46a , Fig.46b , Fig.46c and Fig.46d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.02wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0057] Fig.47a , Figure 47b , Fig.47c and Fig.47d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.03wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0058] Fig.48a , Figure 47b , Fig.47c and Fig.47d In the embodiment of the present invention, the pressing pressure is 300 MPa, the sintering conditions are 800 ° C for 2 h, and the CuO-TiO 2 The addition amount of sintering aid is 2wt%, Al 2 O 3 When the ratio of Al / Al is 40:60 and the AlN content is 0.5wt%, the Al 2 O 3 / Al composite material and Al-12Si-0.04wt%Sr alloy interface EDS spectrum, O element distribution spectrum in EDS spectrum (500μm), Al element distribution spectrum in EDS spectrum (500μm), Si element distribution spectrum in EDS spectrum (500μm);

[0059] Fig.49a , Fig.49b , Fig.49c , Fig.49d , Fig.49e and Figure 49f They are respectively SEM images, EDS energy spectrum (Al element), EDS energy spectrum (Si element), EDS energy spectrum (Cr element), EDS energy spectrum (Mn element) and EDS energy spectrum (Fe element) of 304 stainless steel and Al-12Si alloy after corrosion for 120 hours in the embodiment of the present invention;

[0060] Fig.50a , Fig.50b , Fig.50c , Fig.50d , Fig.50e and Fig.50f They are respectively SEM images, EDS energy spectrum (Al element), EDS energy spectrum (Si element), EDS energy spectrum (Fe element), EDS energy spectrum (Cr element) and EDS energy spectrum (Ni element) of 316 stainless steel and Al-12Si alloy after corrosion for 120 hours in the embodiment of the present invention;

[0061] Fig.51a , Fig.51b and Fig.51c They are respectively the nitriding layer diagrams of the alloys 12Cr2Ni4A, 15Cr and 20CrMnTi after soft nitriding treatment in the embodiments of the present invention; Fig.52a , Fig.52b and Fig.52c They are respectively the nitriding layer diagrams of the alloys 12Cr2Ni4A, 15Cr and 20CrMnTi after hard nitriding treatment in the embodiments of the present invention;

[0062] Fig.53a , Fig.53b , Fig.53c and Fig.53d They are respectively the surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element) and surface scanning map (Fe element) of the alloy 12Cr2Ni4A after soft nitriding treatment and the Al-12Si alloy after corrosion at 800°C for 120h in the embodiment of the present invention;

[0063] Fig.54a , Fig.54b , Fig.54c and Fig.54d They are respectively the surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element) and surface scanning map (Fe element) of the alloy 15Cr and the Al-12Si alloy after the soft nitriding treatment in the embodiment of the present invention and after corrosion at 800°C for 120h;

[0064] Fig.55a , Fig.55b, Fig.55c and Fig.55d They are respectively the surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element) and surface scanning map (Fe element) of the alloy 20CrMnTi and the Al-12Si alloy after the soft nitriding treatment in the embodiment of the present invention and corrosion at 800°C for 120h;

[0065] Fig.56a , Fig.56b , Fig.56c , Fig.56d and Fig.56e Surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element), surface scanning map (Cr element) and surface scanning map (Fe element) of the alloy 12Cr2Ni4A after hard nitriding treatment and the Al-12Si alloy after corrosion at 800°C for 120h in the embodiment of the present invention;

[0066] Fig.57a , Fig.57b , Fig.57c and Fig.57d They are respectively the surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element) and surface scanning map (Fe element) of the alloy 15Cr and the Al-12Si alloy after corrosion at 800°C for 120h after hard nitriding treatment in the embodiment of the present invention;

[0067] Fig.58a , Fig.58b , Fig.58c , Fig.58d and Fig.58e The surface scanning microstructure map, surface scanning map (Al element), surface scanning map (Si element), surface scanning map (Cr element) and surface scanning map (Fe element) of the alloy 20CrMnTi and the Al-12Si alloy after hard nitriding treatment and corrosion at 800°C for 120 hours in the embodiment of the present invention. DETAILED DESCRIPTION

[0068] Part I Experimental Materials and Methods

[0069] 1. Process flow: In this embodiment, Al powder, Al 2 O 3 Powder was used as the main raw material, and AlN and SiC ceramic particles with different contents were added to prepare Al 2 O 3 / Al composite materials, study the effects of AlN and SiC on Al under different preparation processes 2 O 3 The influence of different processes on the strength and thermal properties of the composite materials and the corrosion resistance of the composite materials prepared by different processes on the Al-12Si-XSr alloy in the aluminum-silicon alloy. Figure 1 shown.

[0070] 2. Test materials and equipment

[0071] 2.1 Test materials: In this example, Al powder, Al 2 O 3 Powder, SiC powder, AlN powder, CuO-TiO 2 The powder is mixed and ground according to a certain ratio, and an appropriate amount of PVA (polyvinyl alcohol) aqueous solution is added and cold pressed and sintered to prepare Al 2 O 3 / Al composite materials; and corrosion resistance tests were carried out in molten Al-12Si-XSr alloys with different Sr contents. In this embodiment, aluminum powder and alumina powder were sieved through a 200-mesh sieve, the particle size of the ceramic particle additive powder was 100-200 nm, and CuO-TiO 2 The powder is prepared by mixing nano copper oxide and nano titanium dioxide in a mass ratio of 1:4; the purity of the nano copper oxide is 99.5wt% and the particle size is 100-200nm; the purity of the nano titanium dioxide is 99.5wt% and the particle size is 100-200nm; both the nano copper oxide and the nano titanium dioxide are produced by Shanghai McLean Biochemical Technology Co., Ltd., and the powder particle size is nanometer level, the copper oxide model is C805373 nano copper oxide, spherical; the titanium oxide model is T818992, titanium dioxide, 99.5%; the relative molecular mass of the polyvinyl alcohol is 180000-200000, and the alcoholysis degree is 98.0-99.0mol%.

[0072] 2.2 Experimental equipment: The main instruments and equipment used in this example and their parameters are shown in Table 1.

[0073] Table 1

[0074]

[0075] 3. Test process:

[0076] 3.1 Al 2 O 3 Preparation of / Al composite materials

[0077] Al powder (purity 99.99wt%), Al 2 O 3 powder (purity 99.99wt%), SiC (or AlN) as ceramic particle additives, and CuO-TiO 2The sintering aids are mixed in a certain ratio to obtain a mixed raw material A; a polyvinyl alcohol (PVA) aqueous solution with a concentration of 3 wt% is added to the mixed raw material A and then fully ground to make it uniformly mixed to obtain a mixed raw material B; the amount of the polyvinyl alcohol (PVA) aqueous solution added is such that the mass fraction of the polyvinyl alcohol (PVA) aqueous solution in the mixed raw material B is 8 wt%. The mixed raw material B is put into a planetary ball mill and ground at a speed of 200 rpm for 2 hours. [If the ball milling speed is too slow or the ball milling time is too short, the powder will be unevenly mixed. If the ball milling speed is too fast or the ball milling time is too long, the aluminum powder will be severely oxidized.] After the ball milling is completed, a mixed raw material C is obtained; then 9 g of the ground mixed raw material C is weighed and put into a mold with a diameter of φ30 mm, and the pressure is increased to 100 MPa, 200 MPa, and 300 MPa at a rate of 800 N / s on a microcomputer-controlled electro-hydraulic servo universal testing machine and maintained for 300 seconds to prepare a prefabricated block of about φ30×6 mm. Then the prefabricated block was heated in a resistance furnace at 10°C / min to 750°C for 2h, 850°C for 2h, 850°C for 1.5h and 800°C for 2h, and then cooled to room temperature. The components of the prepared composite materials are shown in Table 2. In this embodiment, CuO-TiO 2 The amount of sintering aid is 2.0wt%. If CuO-TiO 2 Too little sintering aid is not enough to coat the Al particles, while too much will produce excessive Al 3 Ti.

[0078] Table 2

[0079]

[0080] The above table is Al 2 O 3 The composite material was prepared when the ratio of Al / Al (mass ratio) was 35:65. 2 O 3 The composite materials with CuO / TiO ratio (mass ratio) of 30:70, 40:60, 45:55, 50:50, and 55:45 were used as the control group and the composite materials without CuO-TiO 2 The composite materials were prepared under the condition that the powder was used as a sintering aid to discuss the effect of different Al contents on the properties of the composite materials.

[0081] 3.2 Compatibility test of composite materials and Al-12Si alloy

[0082] The composite material was cut into 2×5×10mm rectangular thin slices for standby use; Al-12Si alloy was modified by adding 0, 0.01%, 0.02%, 0.03%, and 0.04% Sr respectively to form a corrosive medium material. The prepared composite thin slice was inserted into the prepared Al-12Si-XSr alloy melt and kept at 800℃ for 120h for composite corrosion test. Under the same conditions, 12Cr2Ni4A, 15Cr and 20CrMnTi with different nitriding treatments were inserted into the Al-12Si-XSr alloy melt for corrosion control test. After cutting, grinding, polishing and other operations on the corroded samples, the corrosion at the interface between the composite material and the Al-12Si-XSr alloy was observed by scanning electron microscopy, and the diffusion between the composite material and the Al-12Si-XSr alloy was analyzed by energy dispersive spectrometer.

[0083] 4 Characterization of composite materials

[0084] 4.1 Composite material porosity

[0085] The porosity of the composite material was measured by the suspended water weight method: first, the dry weight of the sample was measured, recorded as m 1 Then, soak the sample in distilled water for 120 hours to allow the sample to fully absorb water, and measure the mass of the sample in water, recorded as m 2 Take the sample out of the water and measure the mass of the sample saturated with water, recorded as m 3 During the measurement process, each sample was tested three times and the average value was calculated to reduce the error. The porosity of the composite material can be calculated according to formula 1, where P is the porosity of the sample, m 1 is the dry weight of the sample, m 2 is the mass of the sample in water after absorbing water, m 3 It is the mass of the sample in air after absorbing water.

[0086]

[0087] 4.2 Composite material strength

[0088] The strength of the composite material was tested by a three-point bending test: the composite material was cut into standard bending specimens of 35×3×4mm, and the surfaces of the specimens were polished smooth in sequence; load was applied at a rate of 0.1mm / min on a universal electronic testing machine until the specimen was damaged; the span in the test was 30mm, 5 samples were measured for each group of specimens and the average value was taken to reduce the error; the data was recorded after the test, and the bending strength of the composite material was calculated according to Formula-2; where R is the bending strength (MPa), F is the breaking load (N), L is the span (mm), b is the specimen width (mm), and h is the specimen thickness (mm).

[0089]

[0090] 4.3 Latent heat of phase change and thermal conductivity of composite materials

[0091] The latent heat of phase change of the composite material was obtained by SET ARAM I Abyss evo differential scanning calorimeter, with the heating rate set to 10K / min and the temperature range to 25-800℃. The thermal conductivity of the composite material was measured by Hot Disk thermal constant analyzer (TPS-2500S), with an accuracy of 3% and a test range of 0.01-500W / mK. Hot Disk thermal constant analyzer is the most accurate, fast and convenient analytical instrument for studying the thermal conductivity of materials, and can simultaneously measure the thermal conductivity, thermal diffusion coefficient and heat capacity of materials. In this embodiment, the double-sided method in the Hot Disk thermal constant analyzer was used for the test. Compared with the single-sided method, the data measured by the double-sided method is more accurate and reliable. First, two prepared composite materials were selected and their surfaces were polished smooth, and the instrument probe was placed between the two composite materials and placed in an insulating environment; the measurement power was selected to be 80mW and the measurement time was 1s; each group of tests was measured 5 times and the average value was taken. Before each measurement, 30 minutes should be waited to ensure that the heat generated by the previous measurement has been completely dissipated.

[0092] 5 Compatibility characterization of composite materials and Al-12Si-XSr alloy

[0093] After the composite material was placed in liquid Al-12Si-XSr alloy for 120 hours, the sample was cut and polished along the cross section of the composite material, and the morphology and thickness of the corrosion layer at the interface were observed under a scanning electron microscope; the interface was analyzed by surface scanning and line scanning using an energy X-ray spectrometer.

[0094] Part II Effect of Sintering Process on Al 2 O 3 Influence of packaging effect of / Al composite materials

[0095] 1 Effect of sintering temperature and holding time on the macroscopic morphology of composite materials after sintering

[0096] Figure 2a to Figure 2d The SiC content is 0.5wt%, the pressing pressure is 100MPa and the Al 2 O 3 When the mass ratio of Aluminum to Al is 50:50, the Al 2 O 3 The macroscopic morphology of the sintered / Al composite material. Figure 2a to Figure 2dIt can be seen that when the sintering temperature is 750℃ and maintained for 2h, the composite material is brittle and accompanied by a small amount of leakage, so it is necessary to increase the sintering temperature or extend the sintering time; when the sintering temperature is increased to 850℃ and the sintering time is kept unchanged for 2h, the composite material is overburned; and when the sintering temperature is 850℃ and the sintering time is reduced to 1.5h, the composite material has low strength and there is leakage of aluminum liquid; after changing the sintering temperature to 800℃ and the holding time to 2h, the composite material has a certain strength, but a small amount of Al liquid leakage will still occur.

[0097] 2 Effect of pressing pressure on the macroscopic morphology of composite materials after sintering

[0098] Figure 3a to Figure 3f The SiC content is 0.5wt%, the sintering temperature is 800℃ and the temperature is kept for 2h, and the Al 2 O 3 When the ratio of Al / Al is 50:50, the macroscopic morphology of the composite material after sintering under different pressing pressures. Figure 3a to Figure 3f It can be seen that when the pressing pressure of the composite material is greater, the leakage of Al liquid is more serious; this is because the greater the pressing pressure, the smaller the pores in the composite material, and the more difficult it is to meet the volume expansion of Al liquid caused by melting; therefore, a small pressing pressure can effectively prevent Al liquid leakage, but the smaller the pressing pressure, the lower the strength of the composite material, which does not conform to the actual working conditions of the composite material.

[0099] 3 Al 2 O 3 Effect of Al / Al ratio on the macroscopic morphology of composites after sintering

[0100] Figures 4a to 4e The SiC content is 0.5wt%, the sintering temperature is 800℃ and the temperature is kept for 2h, and the pressing pressure is 300MPa. 2 O 3 / Al ratio after sintering. Figures 4a to 4e It can be seen that all the samples in this embodiment have serious Al liquid leakage, and when the Al content in the composite material is lower, the leaked Al liquid is less. However, reducing the Al content in the composite material will reduce the heat storage capacity and thermal conductivity. Therefore, reducing the Al content in the composite material is not an effective way to solve the leakage of Al liquid at high temperature.

[0101] 4 CuO-TiO 2 Effect of sintering aids on the structure of composite materials after sintering

[0102] Figure 5a to Figure 5cThe SiC content is 0.5wt%, the sintering temperature is 800℃ and the temperature is kept for 2h, and the pressing pressure is 300MPa. 2 O 3 / Al ratio when adding CuO-TiO 2 The macroscopic morphology of the composite material after sintering with sintering aid. 2 The addition amount of sintering aid is 2wt%, CuO-TiO 2 CuO accounts for 20wt% of the sintering aid, and the rest is TiO 2 .from Figure 5a to Figure 5c It can be seen that when the Al content in the composite material is less than 70wt%, there is no Al liquid leakage after the composite material is sintered. When the Al content in the composite material is greater than 70wt%, a small amount of Al liquid leakage occurs after sintering.

[0103] Figure 6a Without adding CuO-TiO 2 SEM image of the composite material after sintering the additive, it can be observed that the alumina particles in the composite material are different from the Al before sintering. 2 O 3 There is not much difference in particle size. Figure 6b To add CuO-TiO 2 The sintering morphology of the composite material after sintering aid Figure 6a Compared with CuO-TiO 2 Sintering aids can promote Al 2 O 3 Sintering makes Al 2 O 3 The particles are connected to each other and distributed in a network pattern, which prevents the leakage of aluminum liquid to a certain extent. 2 O 3 and TiO 2 There are a lot of gaps in the structure. 4+ With Al 3+ Can diffuse; due to the different charges, Ti4 + With Al 3+ A cation vacancy is generated during substitution, which increases the vacancy concentration, thereby increasing the diffusion coefficient and promoting Al 2 O 3 Sintering. Its defect equation is shown in Equation-3.

[0104]

[0105] In the above formula Indicates Ti4 + Replace Al 3+ After that, it carries a unit positive charge, V A 'l ″ means Al 3+ The vacancy carries 3 units of negative charge. The equilibrium constant can be calculated based on formula-3, as shown in formula-4.

[0106]

[0107] It can be concluded that TiO 2 The concentration of vacancies will increase, and the diffusion coefficient is proportional to the vacancy concentration, so TiO 2 It will increase the diffusion coefficient and thus accelerate sintering.

[0108] Figure 7a and 7c They are Figure 6a and Figure 6b After enlarging the image, compare Figure 7b and Figure 7d It can be found that CuO-TiO 2 Sintering aids can not only promote Al 2 O 3 The particles are reticulated, and because aluminum will react with TiO 2 Or CuO reacts to form Al 2 O 3 This in-situ generated Al 2 O 3 A layer of Al will be formed on the surface of Al powder agglomerates. 2 O 3 Thin films, such as Figure 7d As shown, the reaction formula is shown in Formula-4; without adding CuO-TiO 2 The composite material of sintering aid does not have complete Al 2 O 3 Film formation, such as Figure 7b As shown. This Al 2 O 3 The film divides the Al matrix into regions of different sizes. 2 O 3 The film will also wrap the aluminum liquid to prevent leakage; the Ti generated by the reaction diffuses into the Al and forms Al with the Al matrix. 3 Ti phase exists in the Al matrix, such as Figures 8a to 8b As shown. Since the content of CuO is very small, the generated Cu will dissolve in Al to form a solid solution.

[0109] 4Al+3TiO 2 =2Al 2 O 3 +3Ti(in Al) (Formula-4)

[0110] 2Al+3CuO=Al 2 O3 +3Cu(Solid solution) (Formula-5)

[0111] 5. Summary of this part

[0112] This part mainly studies the process conditions to prevent Al liquid leakage during the sintering process of the composite material, as well as the CuO-TiO 2 The influence of sintering aids on the structure of composite materials; the main conclusions are as follows:

[0113] ① The factors that affect the sintering process of composite materials are mainly sintering temperature and holding time. Experiments have shown that when the sintering temperature is too low or the holding time is too short, the composite material will be brittle and have low strength after sintering; when the sintering temperature is too high or the holding time is too long, over-burning will occur; when the SiC content in the composite material is 0.5wt%, the pressing pressure is 100MPa and the Al 2 O 3 When the ratio of CuO / Al is 50:50, the sintering process is 800℃ and the best effect is achieved when it is maintained for 2h. ② The smaller the pressing pressure, the less Al liquid leakage after the composite material is sintered. However, considering the actual working conditions, reducing the pressing pressure is not an effective way to solve the Al liquid leakage in the composite material. ③ Adding CuO-TiO 2 Sintering aids can effectively prevent the leakage of Al liquid during the sintering process of composite materials. The mechanism is: CuO, TiO 2 It will react with the Al in the composite material and form a layer of Al 2 O 3 The film will cover the Al liquid to prevent leakage.

[0114] Part III Effects of SiC and AlN particles on mechanical and thermal physical properties of composites

[0115] 1 Effect of SiC on mechanical and thermal physical properties of composite materials

[0116] Figure 9a For Al 2 O 3 When the SiC content and pressing pressure are increased with the SiC / Al ratio of 35:65, the porosity of the composite material changes with the SiC content and pressing pressure. It can be seen from the figure that the porosity of the composite material increases first, then decreases, and finally remains basically unchanged with the increase of SiC content; and the porosity decreases with the increase of pressing pressure, which fully demonstrates that increasing the pressing pressure can effectively reduce the porosity of the composite material; when the pressing pressure is 300MPa, the porosity of the composite material is the smallest, and the porosity does not change significantly with the SiC content. When the pressing pressure is 300MPa and the SiC content is 1wt%, the porosity of the composite material is the smallest, which is 27.8%. At the same time, defects in the composite material also affect the change of its porosity. Figures 10a to 10dThe side macroscopic photos of sintered samples with different SiC contents are shown in Figure 1. Figures 10a to 10d In the figure, the pressing pressures from left to right in each photo are 100Mpa, 200Mpa, and 300Mpa. As can be seen from the figure, when the SiC content is 0, no obvious cracks are produced in the composite materials with different pressing pressures. As the SiC content increases to 0.5wt%, a large number of cracks appear in the composite material, causing its porosity to increase. When the SiC content continues to increase to 1wt%, the cracks in the composite material become very few or even disappear, causing the porosity to decrease. When the SiC content is 1.5wt%, there is no significant change in the number of cracks, so the porosity does not change significantly. Figures 10a to 10d It can also be seen that the smaller the pressing pressure, the more cracks there are. Increasing the pressing pressure helps to reduce the generation of cracks. Analysis shows that the generation of cracks is affected by SiC segregation on the one hand, and by the reaction between SiC and Al, which strengthens the bonding between SiC particles and Al. When the SiC content is low, the reaction is weak, and the addition of SiC ceramic particles increases the porosity of the composite material. Fig.10b , resulting in the most cracks when the SiC content is 0.5wt%. If a certain amount of SiC is added, the reaction between SiC and Al will intensify, making the SiC and Al bond tightly and the porosity decrease. When excessive SiC is added, the SiC particle segregation plays a dominant role and the porosity increases. Fig.10d shown.

[0117] Figure 9b For Al 2 O 3 The bending strength of the composite material changes with SiC content and pressing pressure when the SiC / Al ratio is 35:65. According to the image, it can be obtained that the bending strength of the composite material first decreases with the SiC content, then increases and then decreases, and increases with the increase of pressing pressure. When the pressing pressure is 300MPa and the SiC content is 1.0wt%, the bending strength is the largest, which is 40.81MPa. There are two factors that affect the strength of the composite material, namely the number of cracks in the composite material and the distribution of SiC. When the SiC content in the composite material is 0, no cracks occur, and the SiC particles in the composite material are evenly distributed without segregation. When the SiC content increases to 0.5wt%, although there is no segregation of SiC particles, a large number of cracks are generated, which is the main reason for the decrease in the strength of the composite material. As the SiC content continues to increase to 1wt%, SiC is evenly distributed in the composite material, and the number of cracks in the composite material decreases or even disappears, which improves the strength of the composite material. As the SiC content increases to 1.5wt%, although the number of cracks in the composite material does not change significantly, excessive SiC is enriched in the Al of the composite material. 2 O 3 / Al interface (such as Figures 13a to 13eAs shown in the figure, the local energy of the composite material increases, the stress increases, and the strength decreases.

[0118] Figures 11a to 11e , Figures 12a to 12e , Figures 13a to 13e The surface scanning graphs of the composite material when the SiC content in the composite material is 0.5wt%, 1wt%, and 1.5wt% respectively. When the SiC content in the composite material is 0.5wt% and 1wt%, there is no segregation of SiC particles in the composite material. When the SiC content increases to 1.5wt%, a large amount of SiC particles in the composite material segregate, which is one of the main reasons for the decrease in the strength of the composite material.

[0119] Fig.14a For Al 2 O 3 When the ratio of SiC to Al is 35:65, the thermal conductivity of the composite material changes with SiC content and pressing pressure. The thermal conductivity of the composite material increases with increasing pressing pressure, because increasing pressing pressure can effectively reduce the porosity of the composite material. Since SiC is a material with good thermal conductivity, adding SiC can effectively improve the thermal conductivity of the composite material. At the same time, since the Al in the composite material will react chemically with SiC to form lamellar Al 4 C 3 phase, so under the influence of these two factors, the thermal conductivity of the composite material first rises and then stabilizes, and when the pressing pressure is 300MPa and the SiC content is 0.5wt%, the thermal conductivity of the composite material is the highest, which is 12.43W / mK. 4 C 3 It will undergo hydrolysis reaction with water, resulting in the inability to observe Al after the sample is polished. 4 C 3 However, when the SiC content in the composite material reaches 1.5wt%, the thermal conductivity of the composite material decreases due to the segregation of SiC. Fig.14b For Al 2 O 3 When the SiC / Al ratio is 35:65, the latent heat of the composite material changes with SiC content and pressing pressure. The main factor affecting the latent heat of the composite material is the Al content in the composite material. When the pressing pressure increases, the latent heat of the composite material increases accordingly. This is because increasing the pressing pressure will reduce the porosity in the composite material, thereby slowing down the oxidation of Al in the composite material and ultimately increasing the latent heat of the composite material. As the SiC content increases, the pores in the composite material first increase, then decrease, and finally remain unchanged, causing the trend of the latent heat of the composite material to decrease first, then increase, and finally remain unchanged. At the same time, when the pressing pressure is 300MPa and the SiC content is 1.5wt%, the latent heat of the composite material is the highest, which is 179.92J / g.

[0120] Fig.15a For Al 2 O 3 When the SiC content and pressing pressure are increased, the porosity of the composite material decreases with the increase of pressing pressure, and increases first and then decreases with the increase of SiC content. 2 O 3 When the SiC / Al ratio is 35:65, the porosity change trend of the composite material is consistent. When the SiC content remains unchanged, the porosity of the composite material is the highest when the pressing pressure is 100MPa; the porosity of the composite material is the lowest when the pressing pressure is 300MPa. Among them, when the SiC content of the composite material is 1.5wt% and the pressing pressure is 300MPa, the porosity of the composite material is the smallest, which is 29.3%. Compared with other factors that remain unchanged, the porosity increases by 2.3% when the Al content is 65wt%. This fully shows that reducing the Al content in the composite material will increase the pores in the composite material.

[0121] Fig.15b For Al 2 O 3 The flexural strength of the composite material changes with SiC content and pressing pressure when the SiC / Al ratio is 40:60. 2 O 3 When the ratio of Al / Al is 35:65, the bending strength of the composite pores is consistent. The reason for the change in the bending strength of the composite is related to the Al 2 O 3 The strength of the composite material is the same as when the Al / Al ratio is 35:65. However, since Al is the main matrix that provides strength in the composite material, when the Al content in the composite material decreases, the strength also decreases. And compared with the composite material with an Al content of 65wt%, the strength decreases from the original 40.81MPa to 33.96MPa, a decrease of about 20.17%. Fig.16a For Al 2 O 3 When the SiC content is 40:60, the thermal conductivity of the composite material changes with SiC content and pressing pressure. As the SiC content increases, the thermal conductivity of the composite material first increases and then slowly decreases; as the pressing pressure increases, the thermal conductivity of the composite material gradually increases. This is consistent with the Al 2 O 3When the SiC / Al ratio is 35:65, the thermal conductivity of the composite material has the same trend. When the pressing pressure is 300MPa and the SiC content is 0.5wt%, the thermal conductivity is the highest, which is 10.56W / mK. The main heat conduction in the composite material is Al, so reducing the Al content in the composite material will reduce the thermal conductivity of the composite material, and compared with the composite material with an Al content of 65wt%, the thermal conductivity drops from the original 12.43W / mK to 10.56W / mK, a decrease of about 17.6%. Fig.16b For Al 2 O 3 When the SiC content is 1wt% and the SiC ratio is 40:60, the latent heat of the composite material changes with the SiC content and the pressing pressure. When the pressing pressure is 300MPa and the SiC content is 1wt%, the latent heat of the composite material is the highest, which is 133.48J / g. The latent heat in the composite material is mainly provided by Al during solidification (melting). Therefore, when the Al content in the composite material is reduced from 65wt% to 60wt%, its latent heat value also decreases, and the latent heat decreases from the original 179.92J / g to 133.48J / g, a decrease of 34.79%. When the Al content in the composite material is reduced from 65wt% to 60wt%, the latent heat value also decreases. 2 O 3 When the SiC / Al ratio changes from 35:65 to 40:60, the trend of the change of the thermophysical properties with SiC content and pressing pressure is the same, and the reasons for the change of the mechanical and thermophysical properties of the composite material are also the same. However, due to the reduction of Al content, the flexural strength, latent heat and thermal conductivity of the composite material will decrease.

[0122] Effect of 2AlN on mechanical and thermal physical properties of composites

[0123] Fig.17a It's Al 2 O 3 When the Al / Al ratio is 35:65, the porosity of the composite material changes with the AlN content and the pressing pressure. It can be seen from the figure that the porosity of the composite material first decreases, then increases, and finally remains basically unchanged with the increase of AlN content. And as the pressing pressure increases, the porosity decreases. When the pressing pressure is 300MPa, the porosity of the composite material is the smallest, and the porosity does not change significantly with the AlN content. When the pressing pressure is 300MPa and the AlN content is 0.5wt%, the porosity of the composite material is the smallest, which is 26.2%. At the same time, defects in the composite material are also the main factors affecting its porosity, such as Figures 18a to 18dAs shown in the figure, when the AlN content is 0, there are a few cracks in the composite material; as the SiC content increases to 0.5wt%, the cracks in the composite material disappear, and the porosity decreases; when the AlN content continues to increase to 1wt%, a small number of cracks begin to appear in the composite material, causing the porosity to increase. When the AlN content is 1.5wt%, the number of cracks does not change significantly, so the porosity does not change significantly.

[0124] The generation of cracks is also a major factor affecting the strength of composite materials, such as Fig.17b As shown. The flexural strength of the composite material is the largest when the pressing pressure is the same and the number of cracks is the least, that is, the strength is the largest when the AlN content in the composite material is 0.5wt%. At the same time, pressing pressure is also one of the factors affecting the strength of the composite material. As the pressing pressure increases, the flexural strength of the composite material increases. When the pressing pressure is 300MPa and the AlN content is 0.5wt%, the flexural strength of the composite material is the largest, which is 44.52MPa. Unlike SiC, the AlN ceramic particle additive is always evenly distributed in the composite material and does not react with other components, such as Figures 19a to 19d , Figures 20a to 20d , Figures 21a to 21d As shown. Analysis shows that AlN does not react with Al, and the reason for the cracks is only related to the segregation of AlN. When the AlN content is gradually increased, AlN segregates, resulting in greater stress around it, which eventually leads to cracks.

[0125] Fig.22a For Al 2 O 3 When the AlN / Al ratio is 35:65, the thermal conductivity of the composite material changes with the AlN content and pressing pressure. The thermal conductivity of the composite material increases with the pressing pressure, because increasing the pressing pressure can effectively reduce the porosity of the composite material. At the same time, the thermal conductivity of the composite material is also affected by the ceramic particle content and the number of cracks. Since AlN is a material with good thermal conductivity, adding AlN can effectively improve the thermal conductivity of the composite material. However, when the AlN content in the composite material is 0.5wt%, due to the influence of cracks, the thermal conductivity increase rate decreases until the AlN content in the composite material is 1wt%, and the thermal conductivity shows a downward trend. When the pressing pressure is 300MPa and the AlN content is 1wt%, the bending strength of the composite material is the largest, which is 15.88W / mK.

[0126] Figure 22b For Al 2 O 3When the AlN / Al ratio is 35:65, the latent heat of the composite material changes with the AlN content and the pressing pressure. The main factor affecting the latent heat of the composite material is the Al content in the composite material. When the pressing pressure increases, the latent heat of the composite material increases. This is because increasing the pressing pressure will reduce the porosity in the composite material, thereby slowing down the oxidation of Al in the composite material and ultimately increasing the latent heat of the composite material. At the same time, since the number of cracks in the composite material is the smallest when the AlN content is 0.5wt%, the oxidation of Al at this time is slow and the latent heat is the largest.

[0127] Fig.23a For Al 2 O 3 The porosity of the composite material changes with AlN content and pressing pressure when the ratio of Al / Al is 40:60. 2 O 3 When the AlN / Al ratio is 35:65, the porosity of the composite material changes in the same way, all showing a decrease first, then an increase, and finally remaining unchanged. The porosity of the composite material decreases with the increase of the pressing pressure. When the pressing pressure is 100MPa, the porosity of the composite material is at the maximum level when the ceramic particle additive content remains unchanged, and the porosity of the composite material is at the minimum level when the pressing pressure is 300MPa. However, when the Al content in the composite material decreases, the porosity shows an overall upward trend. When the AlN content in the composite material is 0.5wt% and the pressing pressure is 300MPa, the porosity of the composite material is the lowest, which is 28.74wt%. Compared with other factors that remain unchanged, the porosity of the composite material increases by 9.4% when the Al content is 45wt%. At the same time, when the AlN content in the composite material is 1wt% and the pressing pressure is 100MPa, the porosity of the composite material is the largest, which is 42.88%. Compared with other factors that remain unchanged, the porosity of the composite material increases by 14.1% when the Al content is 45wt%.

[0128] Figure 23b For Al 2 O 3 When the AlN / Al ratio is 40:60, the bending strength of the composite material changes with the AlN content and pressing pressure. It can be seen from the curve that the bending strength of the composite material increases with the increase of the pressing pressure. When the ceramic particle additive remains unchanged, the bending strength of the composite material is the lowest at 100MPa and the highest at 300MPa. At the same time, with the increase of AlN content, the bending strength of the composite material shows a trend of first rising and then falling. When the pressing pressure remains unchanged and the AlN content is 0.5wt%, the bending strength of the composite material is the highest. This is consistent with the Al 2 O 3 When the ratio of Al / Al is 35:65, the change trend of the flexural strength of the composite material is the same.2 O 3 When the Al / Al ratio is 40:60, the flexural strength of the composite material is the highest at 300MPa, when the AlN content is 0.5wt%, which is 43.5MPa; and the lowest at 100MPa, when the AlN content is 1.5wt%, which is 13.04MPa. 2 O 3 When the Al / Al ratio was 35:65, the maximum strength of the composite material decreased by 3.5%.

[0129] Fig.24a For Al 2 O 3 When the AlN / Al ratio is 40:60, the thermal conductivity of the composite material changes with AlN content and pressing pressure. It can be seen from the curve that the thermal conductivity of the composite material increases with the increase of pressing pressure. When the pressing pressure is 100MPa, the thermal conductivity of the composite material is at the lowest level, and when the pressing pressure is 300MPa, the thermal conductivity of the composite material is at the highest level; at the same time, the thermal conductivity of the composite material shows a trend of first increasing and then decreasing with the increase of AlN content. When the pressing pressure remains unchanged and the AlN content is 0.5wt%, the thermal conductivity of the composite material is the highest. This is consistent with the Al 2 O 3 When the ratio of Al / Al is 35:65, the thermal conductivity of the composite material has the same change trend. In terms of the comprehensive pressing pressure and AlN content, the thermal conductivity of the composite material is the highest at 300MPa when the AlN content is 1wt%, which is 11.73W / mK. 2 O 3 The thermal conductivity of the composite material with an Al / Al ratio of 35:65 was found to decrease by 35.38% when the Al content in the composite material decreased from 45wt% to 40wt%. This is because Al itself is a material with good thermal conductivity, so reducing the Al content in the composite material will also reduce the thermal conductivity.

[0130] Figure 24b For Al 2 O 3 When the Al / Al ratio is 40:60, the latent heat of the composite material changes with AlN content and pressing pressure. According to the image, it can be concluded that the latent heat of the composite material increases with the increase of pressing pressure. At 300MPa, the latent heat of the composite material shows a high level as a whole. At the same time, the latent heat of the composite material shows a trend of first increasing and then decreasing with the increase of AlN content, which is consistent with the Al 2 O 3When the AlN / Al ratio is 35:65, the latent heat of the composite material has the same change trend. When the pressing pressure remains unchanged, when the AlN content is 0.5wt%, the composite material shows a higher latent heat of 151.75J / g. 2 O 3 After comparing the thermal conductivity of the composite material with an Al / Al ratio of 35:65, it was found that when the Al content in the composite material was reduced from 45wt% to 40wt%, the thermal conductivity of the composite material decreased from the original 179.58J / g to 151.75J / g, a decrease of 18.4%. Because only Al elements in the composite material can provide latent heat, reducing the Al content in the composite material will lead to a decrease in latent heat.

[0131] 3 Summary of this part

[0132] This part mainly studies the effects of different pressing pressures and the addition of different types and contents of ceramic particles on the porosity, flexural strength, thermal conductivity and latent heat of the composites. 2 O 3 / Al has an influence on the above properties of composite materials. The main research conclusions are as follows: ① With the increase of pressing pressure, the porosity of the composite material will decrease, while the strength, thermal conductivity and latent heat will increase. ② With the increase of SiC content, the porosity of the composite material shows a trend of increasing first and then decreasing, and the porosity of the composite material is the smallest when the SiC content is 1wt%; the flexural strength of the composite material is affected by the porosity and the number of cracks in the material, showing a trend of first decreasing, then increasing and then decreasing, and the flexural strength of the composite material is the largest when the SiC content is 1wt%; the thermal conductivity of the composite material is affected by the porosity, the number of cracks and the content of SiC particles, showing a trend of first increasing and then decreasing, but the degree of decrease is small, and the thermal conductivity of the composite material is the largest when the SiC content is 0.5wt%; the latent heat of the composite material shows a trend of first decreasing and then increasing, and the latent heat of the composite material is the largest when the SiC content is 1wt%. ③ With the increase of AlN content, the porosity of the composite material decreases first and then increases. When the AlN content is 0.5wt%, the porosity of the composite material is at the minimum level; the flexural strength of the composite material increases first and then decreases. When the AlN content is 0.5wt%, the flexural strength of the composite material is the largest; the thermal conductivity of the composite material increases first and then decreases. When the AlN content reaches 1wt%, the thermal conductivity begins to decrease; the latent heat of the composite material increases first and then decreases. ④ When the Al content in the composite material decreases from 65wt% to 60wt%, the various properties of the composite material decrease to varying degrees. The porosity increases by about 14%, and the compressive strength, thermal conductivity and latent heat decrease by 3.5%, 35% and 18% respectively. ⑤ When SiC is used as a ceramic particle additive in the composite material, at a pressing pressure of 300MPa and Al 2 O 3 When the Al2O3 / Al ratio is 35:65 and the SiC content is 1wt%, the comprehensive performance is the best, with a porosity of 27.8%, a flexural strength of 40.81MPa, a thermal conductivity of 12.43W / mK, and a latent heat of 176.57J / g; when AlN is used as a ceramic particle additive in the composite material, the comprehensive performance is the best when the pressing pressure is 300MPa, the Al2O3 / Al ratio is 35:65 and the AlN content is 0.5wt%, with a porosity of 26.2%, a flexural strength of 44.52MPa, a thermal conductivity of 13.48W / mK, and a latent heat of 179.58J / g.

[0133] Part 4 Compatibility study of composite materials with Al-12Si-XSr alloy

[0134] The results of the previous study show that when SiC is used as a ceramic particle additive in the composite material, the best comprehensive performance is achieved when the SiC content is 1wt%; when AlN is used as a ceramic particle additive, the best comprehensive performance is achieved when the AlN content is 0.5wt%. At the same time, the Al-12Si alloy has better heat storage capacity and cycle durability after Sr modification. Therefore, this section takes the above-mentioned composite materials as research objects to study their compatibility with the Al-12Si-XSr alloy. At the same time, the compatibility of 5 common container materials with the Al-12Si alloy is studied for comparison.

[0135] 1Al 2 O 3 Effect of Si / Al composites on compatibility with Al-12Si-XSr alloy

[0136] Figures 25a to 25e Al-12Si-XSr alloy and Al 2 O 3 SEM images of the composites with a SiC content of 1wt% and a 120h corrosion time of 35:65 / Al ratio. The left side of each image shows the Al-12Si-XSr alloy matrix, and the right side shows the corresponding composite. The brighter area in the composite is Al. 2 O 3 particles, and the darker area is Al. It can be seen from the figure that Al-12Si-XSr alloy and Al 2 O 3 The interface of the Al-12Si-XSr composite material is clear, and no obvious corrosion layer appears. From a macroscopic point of view, the interface is clearest when the Sr content is 0.04wt%. However, the absence of an obvious corrosion layer does not mean that there is no mutual diffusion of elements between the composite material and the Al-12Si-XSr alloy, so further analysis by EDS is required. Figures 26a to 26d Al-12Si alloy without Sr addition and Al 2 O 3 The surface scanning and line scanning spectrum of the interface of the / Al composite material shows a clear interface. The O element is mainly distributed on the right side of the interface, which is the Al in the composite material. 2 O 3 The O element in the interface. The Al element is distributed on both sides of the interface. The Al element on the left is from the Al-12Si alloy, and the Al element on the right comes from Al 2 O 3 / Al composite material. The Si element is mainly distributed on the left, but because the composite contains 1wt% SiC particles, a small amount of Si element distribution is also detected. However, previous studies have shown that when the SiC content in the composite is 1wt%, no Si element aggregation occurs, so it is believed that the Si element diffuses, and because of the Al in the composite material 2 O 3 Al is encapsulated in it, so the diffusion of Si element can only be carried out through the pores in the composite material and finally distributed around the pores.

[0137] Figures 27a to 27d Al-12Si-0.01Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning maps, according to the map can also clearly observe a clear interface. An area with a higher Si element content was found on the Al-12Si-0.01Sr alloy side at the interface, which is due to the addition of the Sr element. Since the Sr element will attach to the Si element in the Al-12Si-0.01Sr alloy, it will reduce the diffusion ability of the Si element and thus gather at the interface; at the same time, the location where the Si element diffuses is also in the pores in the composite material. Combined with EDS line scanning for comparative analysis, it was found that when the Sr content in the Al-12Si-XSr alloy increased from 0 to 0.01wt%, the intensity and number of the Si element peak on the line scan decreased to a certain extent, which is consistent with the results obtained by the surface scan. Figures 28a to 28e The surface scanning and line scanning maps of the interface between Al-12Si-0.02Sr alloy and Al2O3 / Al composite material are shown in Figure 1. Fig.28b The distribution diagram of C elements: Al and Al 2 O 3 The wetting angle is less than 90° in the range of 700-1000°C, so cracks will occur to a certain extent. Since there are certain gaps at the interface, a certain amount of diamond paste will enter the gaps during the polishing process. In the surface scanning spectrum of the Si element, it was also found that the Si element was concentrated on the Al-12Si-0.02Sr alloy side of the interface, which also shows that the diffusion of the Si element into the composite material is hindered. The main reasons for hindering the diffusion of the Si element are the addition of the Sr element and the generation of gaps at the interface. Combined with EDS line scanning for comparative analysis, it was found that when the Sr content in the Al-12Si-XSr alloy increased from 0.01wt% to 0.02wt%, the intensity and number of the Si element peak on the line scan decreased to a certain extent, which is consistent with the results obtained from the surface scanning analysis.

[0138] Figures 29a to 29d Al-12Si-0.03Sr alloy and Al 2 O3 / Al composite interface surface scanning and line scanning spectrum, when the Sr content increases to 0.03wt%, it is found that the Si element is evenly distributed in the alloy in the EDS surface scanning spectrum, and there is no aggregation at the interface. Combined with the EDS line scanning analysis, it is found that compared with the Sr content of 0.02wt%, the intensity of the Si element on the right side of the interface becomes higher, and a certain degree of aggregation occurs. Therefore, it can be explained that when the Sr content increases to 0.03wt%, the ability of Sr to hinder the diffusion of Si becomes weaker. Figures 30a to 30d Al-12Si-0.04Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning maps, when the Sr content continues to increase to 0.04wt%, in the EDS surface scanning map, the Si element is still evenly distributed in the alloy, and the interface is flat, and no Si element enrichment is found at the interface. Combined with the EDS line scanning analysis, it is found that: compared with the Sr content of 0.03wt%, the intensity of the Si element on the right side of the interface continues to increase, and a certain degree of aggregation also occurs. Therefore, it is inferred that when Si element aggregation occurs at the interface between the Al-12Si-XSr alloy and the composite material, it is believed that the diffusion of the Si element is hindered to a certain extent, and the factors that hinder the diffusion of the Si element mainly include whether there is a gap at the interface and the content of Sr in the Al-12Si-XSr alloy. Because Al and Al 2 O 3 The wettability is poor at 800℃, so a certain degree of gaps will be formed at the interface, and the gaps will inhibit the diffusion of Si element in the alloy into the composite material; the hindering effect of Sr element content on the diffusion of Si element shows a trend of first increasing and then decreasing. When the Sr element content is 0.02wt%, the effect of hindering the diffusion of Si element is the best, and when no Sr element is added, the effect of hindering the diffusion of Si element is the worst.

[0139] Figures 31a to 31e Al-12Si-XSr alloy and Al 2 O 3 SEM images of the composite material with a SiC content of 1wt% and a corrosion ratio of 40:60 for 120 h. The left side of the image shows the Al-12Si-XSr alloy matrix, and the right side shows the corresponding composite material. The brighter area in the composite material is Al. 2 O 3 The darker area of ​​the particles is Al. It can be seen from the image that all corrosion interfaces are clearly visible and no obvious corrosion layer appears. Figures 32a to 32d Al-12Si alloy without Sr addition and Al 2 O 3 / Al composite interface surface scanning and line scanning maps. According to the maps, it is found that when the Sr content in the Al-12Si-XSr alloy is 0, the Si element is evenly distributed and there is no enrichment at the interface. On the right side of the interface, the Si element is still distributed in the pores in the composite material. At the same time, combined with EDS line scanning, it is found that a strong Si element peak is found on one side of the composite material, indicating that when the Al-12Si-XSr alloy does not contain Sr elements, the degree of diffusion of Si elements in the alloy into the composite material is high. Figures 33a to 33d Al-12Si-0.01Sr alloy and Al 2 O 3 / Al composite interface surface scanning and line scanning spectrum, according to the spectrum found in the Al-12Si-0.01Sr alloy side of the interface near the interface found Si element enrichment, and in particles, the size of about 5-10μm, analysis is believed that the diffusion of Si element is hindered and gathered at the interface, and the alloy was added with 0.01wt% Sr element, which is consistent with the conclusion of the previous test. Combined with EDS line scanning analysis, it was found that: when the Sr content in the Al-12Si-XSr alloy increased from 0 to 0.01wt%, the intensity of the Si element peak on the composite side decreased to a certain extent, which is consistent with the surface scanning results. Figures 34a to 34d Al-12Si-0.02Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning atlas, according to the atlas: when the Sr content in the Al-12Si-XSr alloy continues to increase to 0.02wt%, Si element enrichment is still found near the interface on one side of the Al-12Si-XSr alloy, and it is in granular form, with a size of about 20μm, and the Si particle size is larger than that when the Sr content is 0.01wt%, indicating that the diffusion of Si element is hindered. Combined with EDS line scanning analysis, it is found that the Si element content on one side of the composite material is reduced to a certain extent compared with the Sr content of 0.01wt% in the Al-12Si-XSr alloy, indicating that when the Sr content in the alloy is 0.02wt%, its hindering effect on Si element is further enhanced. Figures 35a to 35d Al-12Si-0.03Sr alloy and Al 2 O 3 / Al composite interface surface scanning and line scanning atlas, according to the atlas: when the Sr content in the Al-12Si-XSr alloy continues to increase to 0.03wt%, no Si element aggregation is found at the interface between the alloy and the composite material, and the Si element is evenly distributed in the alloy, indicating that the diffusion of the Si element is less hindered. Combined with EDS line scanning, it is found that when the Sr content in the Al-12Si-XSr alloy is 0.03wt%, the intensity of the Si element increases on the right side of the interface, indicating that when the Sr content is 0.03wt%, the hindering effect on the diffusion of the Si element is weakened compared to when the Sr content is 0.02wt%. Figures 36a to 36d Al-12Si-0.04Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning atlas, according to the atlas can be concluded: when the Sr content in the Al-12Si-XSr alloy continues to increase to 0.04wt%, there is still no Si element enrichment on the Al-12Si-XSr alloy side of the interface, and the Si element is evenly distributed in the alloy. Combined with EDS line scanning analysis, it is found that compared with the Sr content of 0.03wt%, the strength of the Si element in the composite material is further increased, that is, when the Sr content in the Al-12Si-XSr alloy is 0.04%, the hindering effect on the diffusion of the Si element is less than that of the Al-12Si-XSr alloy with a Sr content of 0.03wt%.

[0140] In general, when the preparation process of the composite material is 2 O 3 When the Sr content in the Al-12Si-XSr alloy is different and other conditions are exactly the same, the Sr content in the Al-12Si-XSr alloy has an effect on the diffusion of the Si element, that is, with the increase of the Sr content in the Al-12Si-XSr alloy, its inhibitory effect on the Si diffusion shows a trend of first increasing and then decreasing, and the diffusion inhibition effect is best when the Sr content in the Al-12Si-XSr alloy is 0.02wt%.

[0141] Figures 37a to 37e Al-12Si-XSr alloy and Al 2 O 3 SEM image of the composite material corroded for 120h when the Al / Al ratio is 40:60, the pressing pressure is 300MPa, and the AlN content is 0.5wt%. The left side of the image is the Al-12Si-XSr alloy matrix, and the right side is the corresponding composite material. The brighter area in the composite material is Al 2 O 3 The darker area of ​​the particles is Al. It can be seen from the image that all corrosion interfaces are clearly visible and no obvious corrosion layer appears. Figures 38a to 38dAl-12Si alloy without Sr addition and Al 2 O 3 / Al composite interface surface scanning and line scanning spectrum, according to the spectrum, when the Sr content in the Al-12Si-XSr alloy is 0, the Si element distribution appears on the right side of the interface, that is, on the composite side. However, since AlN is added as a sintering aid in the composite at this time, no Si element is added. At the same time, the SEM spectrum on the right side of the interface shows the Si element, which indicates that the Si element in the alloy has diffused into the composite. The Si element is found to be distributed in a ring shape in the composite, indicating that the Si element is still diffused along the pores in the composite, which is the same as the distribution of Si in the composite with SiC added. At the same time, the area where Si elements gather is found on the alloy side of the interface. This is because the porosity of the composite with AlN sintering aid is lower than that of the composite with SiC added under the same conditions, and the channels for Si element diffusion are reduced. Combined with EDS line scanning analysis, it is found that there is a high-intensity peak of Si element on the right side of the interface, which is consistent with the results of surface scanning analysis.

[0142] Figures 39a to 39d Al-12Si-0.01Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning atlas. According to the atlas, when the Sr content in the Al-12Si-XSr alloy is 0.01wt%, Si element particles with a size of about 10μm appear at the interface close to one side of the alloy, indicating that the diffusion of the Si element is hindered. Combined with EDS line scanning analysis, it is found that the intensity of the Si element peak on the right side of the interface is lower than that when the Sr content is 0, that is, when the Sr content in the alloy increases from 0 to 0.01wt%, the diffusion of the Si element is hindered to a certain extent.

[0143] Figures 40a to 40d Al-12Si-0.02Sr alloy and Al 2 O 3 / Al composite interface surface scanning and line scanning atlas, according to the atlas, when the Sr content in the Al-12Si-XSr alloy is 0.02wt%, cracks are found at the interface between the alloy and the composite material, and the width is about 5μm. Due to the existence of cracks, the Si content on the right side of the interface is significantly reduced. At the same time, the density of Si elements near the interface on the alloy side is higher than that far from the interface. At the same time, EDS line scanning shows that the intensity of the Si element peak in the composite material is reduced compared to when the Sr content in the alloy is 0.01wt%.

[0144] Figures 41a to 41d Al-12Si-0.03Sr alloy and Al 2 O3 / Al composite material interface surface scanning and line scanning atlas. According to the atlas, when the Sr content in the Al-12Si-XSr alloy is 0.03wt%, there is no obvious Si element aggregation area at the interface of the sample. Combined with EDS scanning analysis, it is found that compared with the Sr content of 0.02wt%, the intensity of the Si element peak on the right side of the interface is increased, which means that when the Sr element in the alloy increases to 0.03wt%, the hindering effect on the diffusion of the Si element is weaker than that of the alloy with Sr element of 0.02wt%. Figures 42a to 42d It can be seen from the spectrum that when the Sr content in the Al-12Si-XSr alloy is 0.04wt%, the interface of the sample is clearly visible, and no obvious Si element aggregation is observed in the alloy. Combined with EDS scanning analysis, it is found that compared with the Sr content of 0.03wt%, the intensity of the Si element peak on the right side of the interface is still increased, indicating that when the Sr content in the alloy increases to 0.04wt%, the hindering effect of Sr element on the diffusion of Si element is weakened. Figures 43a to 43e Al-12Si-XSr alloy and Al 2 O 3 SEM image of the composite material corroded for 120h when the Al / Al ratio is 40:60, the pressing pressure is 300MPa, and the AlN content is 0.5wt%. The left side of the image is the Al-12Si-XSr alloy matrix, and the right side is the corresponding composite material. The brighter area in the composite material is Al 2 O 3 The darker area of ​​the particles is Al. It can be seen from the image that all corrosion interfaces are clearly visible, and there is no obvious corrosion layer. When the Sr content in the Al-12Si-XSr alloy is 0.04wt%, its interface is the smoothest and clearest. Figures 44a to 44d Al-12Si alloy without Sr addition and Al 2 O 3 The surface scanning and line scanning spectrum of the interface of the Al-12Si-XSr composite material show that when the Sr content in the Al-12Si-XSr alloy is 0, the interface of the sample is clearly visible. Since AlN is added as a sintering aid in the composite material, Si element particles appear at the interface on the Al-12Si-XSr alloy side. According to the EDS line scanning analysis, a Si element peak is found on the right side of the interface. Figures 45a to 45d Al-12Si-0.01Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning maps. According to the maps, when the Sr content in the Al-12Si-XSr alloy is 0.01wt%, the Si element in the alloy on the left side of the interface is more evenly distributed in the matrix, and no Si element aggregation occurs near the interface. According to the EDS line scanning analysis, a higher intensity Si element peak was found in the composite material on the right side of the interface, which is equivalent to the Si element peak when the Sr content in the alloy is 0.

[0145] Figures 46a to 46d Al-12Si-0.02Sr alloy and Al 2 O 3 / Al composite material interface surface scanning and line scanning atlas. According to the atlas, when the Sr content in the Al-12Si-XSr alloy is 0.02wt%, there is a certain amount of Si element aggregation near the interface in the alloy on the left side of the interface. Its shape is granular and the size is about 5-10μm. Combined with EDS line scanning, it is found that only some weaker Si element peaks appear in the composite material on the right side of the interface. This shows that when the Sr content in the alloy is 0.02wt%, the inhibition of Si element diffusion is improved compared with the Sr content of 0.01wt%. Figures 47a to 47d Al-12Si-0.03Sr alloy and Al 2 O 3 / Al composite interface surface scanning and line scanning spectrum, according to the spectrum, when the Sr content in the Al-12Si-XSr alloy is 0.03wt%, no obvious Si element aggregation is found at the interface, and the Si element is distributed more evenly in the alloy. Combined with EDS line scanning, it is found that some Si element peaks appear in the composite material on the right side of the interface, and there is a certain upward trend compared to the Sr content of 0.02wt% in the alloy, indicating that when the Sr content increases from 0.02wt% to 0.03wt%, the hindering effect of Sr on the diffusion of Si elements in the alloy is on a downward trend. Figures 48a to 48d Al-12Si-0.04Sr alloy and Al 2 O 3 / Al composite interface surface scanning and line scanning spectrum, according to the spectrum, when the Sr content in the Al-12Si-XSr alloy continues to increase to 0.04wt%, there is still no obvious Si element aggregation at the interface, and the Si element is distributed more evenly in the alloy. Combined with EDS line scanning, it is found that some Si element peaks appear in the composite material on the right side of the interface, and there is a certain upward trend compared to the Sr content of 0.03wt% in the alloy, indicating that when the Sr content increases from 0.03wt% to 0.04wt%, the hindering effect of Sr on the diffusion of Si elements in the alloy is still on a downward trend.

[0146] 2 Study on compatibility of iron-based container materials and Al-12Si alloy

[0147] Tan Yonggang analyzed Fe-based alloys that have not been nitrided and pointed out that no Fe-based alloy can be used as a packaging material for Al-Si alloys at 800°C. Therefore, this embodiment uses 304 stainless steel, 316 stainless steel, and 12Cr2Ni4A, 15Cr, and 20CrMnTi alloys that have undergone different nitriding treatments as packaging materials to analyze their compatibility with Al-Si alloys.

[0148] 2.1 Compatibility study of stainless steel and Al-12Si alloy

[0149] Figures 49a to 49f , Figures 50a to 50f The SEM photos and energy spectra of 304 stainless steel and 316 stainless steel and Al-12Si alloy after corrosion at 800℃ for 120h are shown. According to the images, both stainless steels have undergone serious corrosion and two different corrosion areas have been produced. The relevant literature points out that Fe-based alloys will react chemically with molten Al-Si alloys. According to the different Si content during the reaction, two Al-Fe-Si-Cr compounds with different Si content will be generated. The compound with lower Si content is generated near the interface on one side of the Al matrix, and its morphology is long needle-shaped, and there are defects around it; the compound with higher Si content appears on one side of the Al matrix away from the interface, and its morphology is square sheet-shaped. Since the corrosion layer thickness of 304 stainless steel is greater than that of 316 stainless steel, 316 stainless steel is more resistant to corrosion of Al-12Si alloy. And compared with the composite material prepared in this embodiment, 304 stainless steel and 316 stainless steel are not suitable as container materials for Al-12Si heat storage alloy. Figure 51a to Figure 51c , Figure 52a to Figure 52c The 12Cr2Ni4A, 15Cr and 20CrMnTi after soft nitriding and hard nitriding treatments respectively. Compared with hard nitriding, the nitriding layer of the alloy after soft nitriding is thicker. Figures 53a to 53d , Figures 54a to 54d , Figures 55a to 55dThese are the SEM photos and EDS spectra of 12Cr2Ni4A alloy, 15Cr alloy and 20CrMnTi alloy and Al-12Si alloy after corrosion at 800℃ for 120h under the soft nitriding process. At 800℃, all alloys treated with soft nitriding reacted with Al-12Si alloy to varying degrees, and there were a certain number of defects. By comparing the corrosion resistance of different alloys under the soft nitriding process, we found that the corrosion layer of 20CrMnTi alloy was the densest, so it had the strongest corrosion resistance to Al-12Si alloy. Relevant literature shows that Fe-based alloys will react chemically with Al-Si alloys to generate two Al-Fe-Si-Cr compounds with different Si contents, namely, long needle-shaped compounds with low Si content and square plate-shaped compounds with high Si content. However, alloy elements such as Cr and Ni were added to the alloys in this experiment, and according to the EDS spectrum, we found that alloy elements such as Cr and Ni also diffused, so compounds containing Al, Fe, Si, Cr, Ni and other elements were generated. The research by Zhao Shuguo and others pointed out that the Cr, Ni and Mn elements in the alloy will make the tip of the long needle-shaped compound generated by the reaction of Fe-based alloy and Al-Si alloy blunt and the length of the needle shorten, thereby reducing the stress of the long needle-shaped compound on its surroundings, reducing defects in the alloy, making the alloy structure denser, and thus improving corrosion resistance; among them, the Cr element has the strongest ability to change the long needle-shaped compound.

[0150] Figures 56a to 56e , Figures 57a to 57d , Figures 58a to 58e These are the SEM photos and EDS spectra of 12Cr2Ni4A alloy, 15Cr alloy, 20CrMnTi alloy and Al-12Si alloy after hard nitriding treatment at 800℃ for 120h. The results are similar to those of the alloys after soft nitriding treatment. The 20CrMnTi alloy has the least defects, the densest structure, and increased corrosion resistance. Compared with other experimental alloy steels, it has slightly better corrosion resistance to Al-12Si alloy. Comparing the corrosion resistance of the same alloys after different nitriding treatments to Al-12Si alloy, it is found that the alloys after soft nitriding treatment have slightly better corrosion resistance to Al-12Si alloy than those after hard nitriding treatment, and the presence of deep C accelerates the corrosion process. However, the specific corrosion mechanism needs further study. Comparing the corrosion resistance of different alloys under the same nitriding process, the 20CrMnTi alloy has the strongest corrosion resistance to Al-Si alloy, followed by 15Cr and 12Cr2Ni4A; comparing the corrosion resistance of the same alloys under different processes, we found that the soft nitrided alloy has stronger corrosion resistance. However, all alloys showed corrosion layers to varying degrees, and the Al 2 O 3After the corrosion of the / Al composite material, the interface is clear and no obvious corrosion layer appears. Therefore, the Al prepared in this embodiment 2 O 3 / Al composite materials can better meet the various performance requirements of heat storage material containers.

[0151] 3 Summary of this part

[0152] This part mainly studies the compatibility of Al-12Si-XSr alloys with different Sr contents and four different composite materials at high temperatures. The diffusion of the corresponding elements in the process was analyzed by SEM line scanning and surface scanning. For comparison, the corrosion resistance of two stainless steels and 12CrMnTi alloy, 15Cr alloy, and 20CrMnTi alloy after soft nitriding and hard nitriding to Al-12Si alloy was also studied. The main research results are as follows: ① The Al content of woven fabrics 2 O 3 After the Al / Al composite material was corroded by Al-12Si-XSr alloy for 120h, the Si element in the Al-12Si-XSr alloy diffused into the composite material to varying degrees, but it did not react chemically with the Al-12Si-XSr alloy, and the interface was clearly visible. The main factor affecting the diffusion of Si elements in the Al-Si alloy into the composite material is the porosity of the composite material. The larger the porosity, the easier it is for the Si element to diffuse. When 0.5wt% AlN is added to the composite material, the porosity is the smallest. ② In the Al-12Si-XSr alloy, when the Sr element content is 0, the Si element in the alloy has a long needle-like morphology. When the Sr element is added, the Sr element will preferentially attach to the surface of the Si element, thereby preventing the Si element from growing at high temperature, and due to the attachment of the Sr element, the diffusion of the Si element in the alloy is hindered. The interface between the Al-12Si-XSr alloy and the composite material will also hinder the diffusion of the Si element in the alloy, and the Si element in the alloy will often have a certain degree of aggregation at the interface, and often presents a granular state. ③ After nitriding and soft nitriding treatment, 12Cr2Ni4A alloy, 15Cr alloy, 20CrMnTi alloy, 304 stainless steel and 316 stainless steel are not resistant to the corrosion of Al-12Si alloy. After being corroded by Al-12Si alloy at 800℃ for 120h, two different corrosion areas appeared. The Si content of the α region is low, the morphology is long needle-shaped, and defects are generated around it; the Si content of the β region is high, and the morphology is square. Elements such as Cr, Mn, and Ni in Fe-based alloys can change the morphology of the α region phase, shorten the length of the needle, and passivate the sharp corners, which can effectively reduce the defects in the alloy. The Cr element has the best effect on shortening the length of the α region phase and passivating the sharp corners, but it cannot effectively eliminate the defects in the α region phase.

[0153] In summary, the present invention uses Al as the heat storage material. 2 O 3 Preparation of Al for framework material 2 O 3 / Al composite materials, and SiC, AlN ceramic particle additives and CuO-TiO 2 Sintering aids, study the effects of ceramic particle additives on the mechanical properties, thermal conductivity and heat storage capacity of composite materials; study CuO-TiO 2 The effect of sintering aids on the microstructure of composite materials was also studied. 2 O 3 The compatibility of Fe / Al composite materials as container materials with Al-12Si alloy was studied. For comparison, the compatibility of 5 commonly used Fe-based containers with Al-12Si alloy was also studied. The main conclusions are as follows:

[0154] ① The process factors that affect the sintering of composite materials mainly include sintering temperature, holding time and pressing pressure. However, changing the preparation process cannot effectively prevent the leakage of Al liquid in the composite material at high temperature. 2 Sintering aids can effectively solve the problem of Al liquid leakage during the sintering process of composite materials. ② With the increase of SiC content, the porosity of the composite material shows a trend of first increasing and then decreasing, and the porosity of the composite material is the smallest when the SiC content is 1wt%; the flexural strength shows a trend of first decreasing, then increasing and then decreasing, and the flexural strength of the composite material is the largest when the SiC content is 1wt%; the thermal conductivity shows a trend of first increasing and then decreasing, but the degree of decrease is small, and the thermal conductivity of the composite material is the largest when the SiC content is 0.5wt%; the latent heat shows a trend of first decreasing and then increasing, and the latent heat of the composite material is the largest when the SiC content is 1wt%. When the pressing pressure is 300MPa and Al 2 O 3 When the Al / Al ratio is 35:65 and the SiC content is 1wt%, the comprehensive performance is the best, with a porosity of 27.8%, a flexural strength of 40.81MPa, a thermal conductivity of 12.43W / mK, and a latent heat of 176.57J / g. ③ With the increase of AlN content, the porosity of the composite material decreases first and then increases. When the AlN content is 0.5wt%, the porosity of the composite material is the lowest level; the flexural strength shows a trend of first increasing and then decreasing. When the AlN content is 0.5wt%, the flexural strength of the composite material is the largest; the thermal conductivity shows a trend of first increasing and then decreasing. When the AlN content reaches 1wt%, the thermal conductivity begins to decline; the latent heat shows a trend of first increasing and then decreasing. When the pressing pressure is 300MPa and the AlN content is 1wt%, the thermal conductivity begins to decline. The latent heat shows a trend of first increasing and then decreasing. 2 O 3When the Al / Al ratio is 35:65 and the AlN content is 0.5wt%, the comprehensive performance is the best, with a porosity of 26.2%, a bending strength of 44.52MPa, a thermal conductivity of 13.48W / mK, and a latent heat of 179.58J / g. ④ When the Al content in the composite material is reduced from 65wt% to 60wt%, the various properties of the composite material have decreased to varying degrees, among which the porosity increased by about 14%, and the compressive strength, thermal conductivity and latent heat decreased by 3.5%, 35% and 18% respectively. ⑤ After the composite material was corroded by Al-12Si-XSr alloy at 800℃ for 120h, the Si element in the Al-12Si-XSr alloy diffused into the composite material to varying degrees, but the composite material did not react chemically with the Al-12Si-XSr alloy, and the interface was clearly visible. The main factor affecting the diffusion of Si element in Al-Si-XSr alloy into the composite material is the porosity of the composite material. The larger the porosity, the easier it is for Si element to diffuse. When 0.5%wt AlN is added to the composite material, the porosity is the smallest. After adding Sr element to Al-Si-XSr alloy, Sr will adhere to Si element in the alloy, which can also hinder the diffusion of Si element into the composite material to a certain extent. The 12Cr2Ni4A alloy, 15Cr alloy, 20CrMnTi alloy, 304 stainless steel and 316 stainless steel after nitriding treatment are not resistant to the corrosion of Al-12Si alloy. They are severely corroded after being corroded by Al-12Si alloy at 800℃ for 120h. The Al prepared by the present invention 2 O 3 The / Al composite material is significantly better than the above-mentioned steel in terms of corrosion resistance to Al-12Si alloy liquid, and can meet various performance requirements of heat storage material containers.

Claims

1. A method for preparing an Al2O3-Al composite packaging material, characterized in that: The steps include: Step A: mixing aluminum powder, alumina powder, CuO-TiO2 powder and ceramic particle additive powder uniformly to obtain mixed raw material A; CuO-TiO2 powder is prepared by mixing nano copper oxide and nano titanium dioxide in a mass ratio of 1:3-5; the purity of nano copper oxide is greater than or equal to 99.5wt%, and the particle size is 100-200nm; the purity of nano titanium dioxide is greater than or equal to 99.0wt%, and the particle size is 100-200nm; the mass ratio of aluminum powder to aluminum oxide powder is 50-65: 35-50; in the mixed raw material A: the mass fraction of CuO-TiO2 powder is 1.5-2.0wt%, and the mass fraction of ceramic particle additive powder is 0.5-1.5wt%; aluminum powder and aluminum oxide powder are both sieved through a 200-mesh sieve; the particle size of the ceramic particle additive powder is 100-200nm; the ceramic particle additive powder is SiC powder or AlN powder; Step B: adding polyvinyl alcohol aqueous solution to mixed raw material A and grinding them thoroughly to obtain mixed raw material B; the mass fraction of the polyvinyl alcohol aqueous solution in the mixed raw material B is 6-10wt%; the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 2-5wt%, the relative molecular mass of polyvinyl alcohol is 180000-200000, and the alcoholysis degree is 98.0-99.0mol%; Step C: placing the mixed raw material B in a ball mill for ball milling, and after the ball milling is completed, a mixed raw material C is obtained; the ball milling speed is 160-220 rpm, and the ball milling time is 1-3 hours; Step D: cold-pressing the mixed raw material C to obtain a prefabricated block; during the cold-pressing, the pressure is increased to 100-300 MPa at a rate of 700-900 N / s and maintained for 250-350 seconds; Step E: placing the prefabricated block in a resistance furnace for sintering, and cooling it to room temperature with the furnace after sintering to obtain an Al2O3-Al composite packaging material; during sintering, first heat the prefabricated block to 750-850°C at 8-12°C / min, keep it warm for 1.5-2h, and then cool it to room temperature with the furnace.

2. The method for preparing the Al2O3-Al composite packaging material according to claim 1, characterized in that: The mass ratio of nano copper oxide to nano titanium dioxide in CuO-TiO2 powder is 1:

4.

3. The method for preparing the Al2O3-Al composite packaging material according to claim 1, characterized in that: In step A, the purity of the aluminum powder and the aluminum oxide powder are both 99.99wt%.

4. Use of an Al2O3-Al composite packaging material, characterized in that: The Al2O3-Al composite packaging material as described in any one of claims 1 to 3 is used to encapsulate aluminum-silicon alloy phase change heat storage material.

5. The use of the Al2O3-Al composite packaging material according to claim 4, characterized in that: The aluminum-silicon alloy phase change heat storage material is an Al-12Si-Xwt%Sr alloy, where X is greater than or equal to 0 and less than or equal to 0.04.

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