A method for preparing an iron-based honeycomb-filled round tube thin-walled structure reinforced aluminum-based composite material

Abstract

The application discloses a preparation method of an iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum-based composite material, and belongs to the technical field of metal composite material preparation.The method comprises the following steps: calculating the required mass of metal ingot according to the volume of the filled pore and the density of the aluminum-based solid material; stacking the iron-based honeycomb filled circular pipe thin-wall structure and aluminum ingot into a corundum ceramic boat, with the aluminum ingot above the thin-wall structure; placing the corundum ceramic boat in a high-temperature resistant glass tube; using a vacuum pump to vacuumize the two; then using oxyhydrogen welding to seal the tube; placing the glass tube in a sintering furnace to perform sintering; after sintering is completed, cooling the furnace to room temperature, then taking out the sample, and the iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum-based composite material is obtained.The method avoids the generation of an oxide layer between the Al / Fe alloy, the obtained composite material interface is complete fusion without obvious boundary, the method is simple and efficient, the excess aluminum-based material can be recycled, and the energy consumption and cost are low.

Description

TECHNICAL FIELD

[0001] The application discloses a preparation method of an iron-based honeycomb-filled circular pipe thin-wall structure reinforced aluminum-based composite material and belongs to the technical field of metal composite material preparation. BACKGROUND

[0002] Aluminum-iron composite materials have the advantages of aluminum-based materials and iron-based materials, high thermal conductivity, wear resistance and corrosion resistance, and the application range is continuously widening.

[0003] Traditional preparation methods of aluminum-iron composite materials are mainly casting and welding processes, and there are still many problems in the process, such as the inability to form effective metallurgical bonding, the difference between the thermal expansion coefficient and the solidification shrinkage rate leading to the easy generation of cracks between Al / Fe, the thick oxide layer easily formed at the interface of the aluminum-iron composite material, the hard and brittle Al / Fe interphase, and the like, which in turn leads to low interfacial bonding strength and poor mechanical properties; and due to the characteristics of aluminum and iron metals, the casting process is only suitable for the composite preparation of simple structures, such as aluminum-coated iron wires, and the aluminum-iron bimetallic components prepared by the casting process often need to be subjected to subsequent heat treatment and the like to enhance the bonding force between aluminum and iron, and the process flow is long, thus greatly limiting the preparation and application of aluminum-iron composite materials.

[0004] Through powder metallurgy means, the defects of aluminum-iron composite materials prepared by casting methods can be avoided, but the aluminum powder operation process is relatively dangerous, the relative cost is high, and the equipment conditions are higher.

[0005] With the development of additive manufacturing technology, complex structure design has become a research hotspot, especially topological structure optimization, which reduces weight while maintaining or improving the performance of parts. For complex structure parts, traditional casting methods are difficult to completely fill the aluminum liquid into the structure inside, and due to the process characteristics, a complex mold often needs to be designed, and the process flow is too long and the air is exposed, which easily leads to the generation of black oxide layer between Al / Fe, seriously affecting the interfacial bonding, and the aluminum and iron do not form an integral structure, the mechanical properties are poor, the aluminum and iron are easy to separate, and due to the existence of loose oxide layer, the heat conduction is hindered, and the thermal conductivity of the composite material is reduced. Although it can be treated by protective gas protection, the equipment requirements are more stringent, the production cost and consumption are increased, which is not conducive to energy saving and emission reduction; and the extrusion casting is not accurate enough in pressure control, which easily causes deformation and damage of complex parts during the aluminum liquid filling process.

[0006] In summary, the present application aims at the shortcomings of high energy consumption, easy deformation of die casting, easy formation of oxide layer at Al / Fe interface, complex process flow and the like of the conventional process, and based on the principle of economic efficiency, the Al / Fe interface well-bonded iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material is prepared quickly and efficiently by adopting vacuum sealing tube treatment, and meanwhile, the consumption of aluminum matrix material is greatly saved, and the energy consumption and cost are reduced. SUMMARY

[0007] The present application aims at the problems of the existing iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material, and provides a preparation method of the iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material, which can quickly and efficiently and at low cost prepare the aluminum matrix composite material with a good bonding interface, and can be widely applied in the fields of aerospace, rail transportation, automobile industry, building and the like.

[0008] The method is realized by the following technical scheme: a preparation method of an iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material, the filling matrix material is an aluminum matrix block, and specifically comprises the following steps:

[0009] (1) The mass of the metal ingot required is calculated according to the volume of the filling pore and the density of the aluminum matrix solid material.

[0010] (2) The iron-based honeycomb filled circular pipe thin-wall structure and the aluminum ingot are stacked in a corundum ceramic boat, the aluminum ingot is above the thin-wall structure, the corundum ceramic boat is placed in a high-temperature resistant glass tube, the vacuum pump is used to vacuumize the two, and then the hydrogen-oxygen welding sealing tube is used.

[0011] (3) The glass tube is placed in a sintering furnace for sintering, after the sintering is completed, the furnace is cooled to room temperature, and then the sample is taken out, and the iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material is obtained.

[0012] Preferably, the mass of the aluminum matrix block material loaded each time in step (1) of the present application is 1.3-1.75 times the calculated mass.

[0013] Preferably, the vacuum degree in step (2) of the present application is 10 -1 -10 -4 Pa.

[0014] Preferably, the sintering condition of the present application is 800-1000℃, and the holding time is 100-300min.

[0015] Another object of the present application is to provide the iron-based honeycomb filled circular pipe thin-wall structure reinforced aluminum matrix composite material prepared by the preparation method.

[0016] Further, the aluminum-based material in the present application is in bulk state, and commercialized aluminum ingot can be purchased according to actual needs or the required components can be added by smelting.

[0017] Further, the aluminum-based material in the present application is in bulk state, and commercialized aluminum ingot can be purchased according to actual needs or the required components can be added by smelting.

[0018] Further, in step (3), the sample in the vacuum tube can be heated and melted by using various sintering and smelting equipment, such as ordinary electric furnace, tube furnace or box furnace, so that the molten aluminum-based material completes the filling process of the iron-based honeycomb filling structure under the action of gravity.

[0019] The iron-based honeycomb filling circular tube thin-wall structure reinforced aluminum-based composite material prepared according to the method has good mechanical properties of the iron-based honeycomb structure material and light weight, high thermal and electrical conductivity of the aluminum-based material, and the use of aluminum-based bulk materials expands the application field and potential of the composite material.

[0020] The present application has the following characteristics: there are many studies on the preparation of Al / Fe bimetal, but most of the composite materials are prepared by extrusion casting or conventional casting, and the casting process easily causes a thick oxide layer between the Al / Fe interface, mechanical bonding of the interface, and seriously affects the performance of the Al / Fe composite material; the filling cell size of the iron-based honeycomb filling circular tube thin-wall structure is small, and the molten aluminum is difficult to penetrate into the iron-based honeycomb filling circular tube thin-wall structure due to the large surface tension and air resistance. The pressure casting method needs to design a complex die casting mold and needs to protect the atmosphere to exclude air to prevent the formation of an oxide layer between Al / Fe, which is a complex process and often needs subsequent heat treatment to optimize the material performance.

[0021] The present application has the following characteristics: there are many studies on the preparation of Al / Fe bimetal, but most of the composite materials are prepared by extrusion casting or conventional casting, and the casting process easily causes a thick oxide layer between the Al / Fe interface, mechanical bonding of the interface, and seriously affects the performance of the Al / Fe composite material; the filling cell size of the iron-based honeycomb filling circular tube thin-wall structure is small, and the molten aluminum is difficult to penetrate into the iron-based honeycomb filling circular tube thin-wall structure due to the large surface tension and air resistance. The pressure casting method needs to design a complex die casting mold and needs to protect the atmosphere to exclude air to prevent the formation of an oxide layer between Al / Fe, which is a complex process and often needs subsequent heat treatment to optimize the material performance.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] (1) There is no need to design and customize a complex casting mold, which overcomes the shortcoming that the aluminum liquid cannot be filled into the complex structure due to the surface tension, and the Al / Fe prepared by the present application has good metallurgical interface bonding.

[0024] (2) The use of bulk materials can reduce costs and improve material utilization compared to powder metallurgy and traditional casting processes. The remaining materials can be recycled due to the vacuum conditions, improving the utilization of the filler matrix material. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Longitudinal and transverse sectional views of the iron-based honeycomb-filled circular pipe thin-walled structure used in the present application placed in a high-temperature-resistant glass pipe.

[0026] Figure 2 Macroscopic morphology of the iron-based honeycomb-filled circular pipe thin-walled structure reinforced aluminum-based composite material after filling in the embodiment of the present application.

[0027] Figure 3 Metallographic phase diagram of the iron-based honeycomb-filled circular pipe thin-walled structure reinforced aluminum-based composite material after filling in the embodiment of the present application.

[0028] Figure 4 EDS spectrum of the iron-based honeycomb-filled circular pipe thin-walled structure reinforced aluminum-based composite material in the embodiment of the present application.

[0029] Figure 5 Macroscopic morphology of the honeycomb-filled circular pipe thin-walled structure reinforced aluminum-based composite material prepared by the die casting method in the comparative embodiment of the present application.

[0030] Figure 6 Metallographic phase diagram of the 316L honeycomb-filled circular pipe thin-walled structure reinforced aluminum-based composite material prepared by the die casting method in the comparative embodiment of the present application. DETAILED DESCRIPTION

[0031] The present application will be further described in detail below in conjunction with the drawings and specific embodiments, but the scope of protection of the present application is not limited to the described content.

[0032] The following embodiments use a high-temperature-resistant glass pipe with an inner diameter of 10 cm. The iron-based honeycomb-filled circular pipe thin-walled structure is placed in the mold as shown in Figure 1 .

[0033] Example 1

[0034] The process steps of the method for preparing a 316L honeycomb-filled circular pipe thin-walled structure composite aluminum material using a vertical pipe furnace in this embodiment are as follows:

[0035] (1) Design the size of the preform: the outer diameter of the filled circular pipe is 10 mm (the actual size is slightly smaller than the design size), the filling cell edge length is 3 mm, the wall thickness is 0.4 mm, and the height is 14 mm; place the 316L honeycomb-filled circular pipe thin-walled structure preform in a corundum ceramic boat as shown in Figure 1 , and add about 2.54 g of pure aluminum (density taken as 2.7 g / cm 3The aluminum ingot is stacked above the thin-walled structure.

[0036] (2) The corundum ceramic boat is placed in a high-temperature resistant glass tube, and the two are vacuumized to 10 - 4 Pa, hydrogen-oxygen sealing tube.

[0037] (3) The glass tube is placed in a vertical tube furnace, the temperature is set to 800°C, and the temperature is kept for 240 minutes. After the furnace is cooled to room temperature, the sample is taken out, and the iron-based honeycomb filled circular pipe thin-walled structure reinforced aluminum-based composite material is obtained, as shown in Figure 2 .

[0038] The mass of the 316L honeycomb filled circular pipe thin-walled structure and the filled thin-walled structure composite aluminum-based material after filling is calculated by using the Archimedes principle to obtain the density of the filled aluminum in the 316L honeycomb filled circular pipe thin-walled structure, and the filling density is 99.7%.

[0039] Figure 3 The metallographic picture shows that there is no obvious oxide layer generated at the Al-Fe bonding interface, and the thin-walled structure is well combined with pure aluminum.

[0040] The line scanning analysis of the aluminum and 316L element composition along the direction perpendicular to the interface is carried out at the aluminum-iron bonding position of the composite material; the results are shown in Figure 4 The EDS spectrum shows that the diffusion of Fe and Cr elements in 316L to the Al matrix is more significant, and the diffusion of Al element to the 316L matrix is less, and the transition region is Fe4Al 13 intermetallic compound, and no black oxide layer is generated between Al / Fe; therefore, the bonding mode of the Al / Fe interface of the obtained 316L honeycomb filled circular pipe thin-walled structure reinforced aluminum-based composite material is metallurgical bonding, and the hardness of the interface bonding is increased due to the generation of intermetallic compound in the Al / Fe transition region. The specific performance characterization is shown in Table 1.

[0041] Example 2

[0042] The process steps of the method for preparing 18Ni300 honeycomb filled circular pipe thin-walled structure composite aluminum material in this embodiment are as follows:

[0043] (1) The design size of the preform is: the outer diameter of the filled circular pipe is 10 mm (the actual size is slightly smaller than the design size), the filling cell edge length is 3 mm, the wall thickness is 0.4 mm, and the height is 14 mm; the 316L honeycomb filled circular pipe thin-walled structure preform is placed in a corundum ceramic boat according to Figure 1 , and an aluminum ingot with a mass of about 2.54 g (the density of pure aluminum is 2.7 g / cm3) is stacked above the thin-walled structure.

[0044] (2) Then place the corundum ceramic boat in a high-temperature resistant glass tube, and use a vacuum pump to vacuumize the two to 10 - 4 Pa, oxyhydrogen sealing tube.

[0045] (3) Place the glass tube in a vertical tube furnace, set the temperature to 1000℃, and keep the temperature for 100 min. After cooling to room temperature, take out the sample, and obtain the iron-based honeycomb filled circular tube thin-walled structure reinforced aluminum-based composite material.

[0046] The mass of the 18Ni300 honeycomb filled circular tube thin-walled structure and the thin-walled structure composite aluminum-based material after filling is calculated by using the Archimedes principle to obtain the density of the aluminum filled in the 18Ni300 honeycomb filled circular tube thin-walled structure, and the filling density is 98.3%.

[0047] The metallographic picture shows that no obvious oxidation layer is generated at the Al-Fe bonding interface, and the 18Ni300 thin-walled structure and pure aluminum interface are well combined. The line scanning analysis of the aluminum and 18Ni300 element composition along the direction perpendicular to the interface at the aluminum-iron bonding position of the composite material shows that the transition region is an Al-Fe intermetallic compound. Therefore, the bonding mode of the Al / Fe interface of the 18Ni300 honeycomb filled circular tube thin-walled structure reinforced aluminum-based composite material is metallurgical bonding. At the same time, the intermetallic compound generated in the Al / Fe transition region causes the hardness of the interface bonding position to increase. The specific performance characterization is shown in Table 1.

[0048] Comparative Example

[0049] The process steps of the 316L honeycomb filled circular tube thin-walled structure reinforced aluminum-based composite material prepared by the die casting method in this example are as follows:

[0050] (1) Fix the 316L honeycomb filled circular tube thin-walled structure in the casting mold, and heat the mold to 450℃ on the platform of the die casting machine.

[0051] (2) Use a medium-frequency induction furnace to melt the pure aluminum ingot into a liquid state. The temperature is controlled at 720℃ during casting. Immediately after casting, press down the die head of the die casting machine to press the aluminum liquid cast in the mold into the 316L honeycomb filled circular tube thin-walled structure. The pressure of the die head is 20 tons, and the pressure holding time of the die head is 15 min.

[0052] (3) Take the mold with the die cast sample from the die casting machine, knock the mold with a hammer, and take out the die cast sample.

[0053] (4) Use a sawing machine to cut off the excess part of the ingot, and use a wire cutting machine to cut the die cast sample from the aluminum matrix. The composite material can be obtained Figure 5 .

[0054] The density of the 18Ni300 honeycomb filled circular tube thin wall structure filled with aluminum is calculated by using Archimedes principle, and the filling density is 98.5%; the metallographic picture of the 18Ni300 honeycomb filled circular tube thin wall structure filled with aluminum is shown in Fig. 3. Figure 6 The Al-Fe bonding interface has obvious black oxide layer, and the interface between the 18Ni300 thin wall structure and the pure aluminum is mechanically bonded; the line scanning analysis of the aluminum and the 18Ni300 element composition along the direction perpendicular to the interface is performed at the aluminum iron bonding position of the composite material, and no Al-Fe intermetallic compound is generated in the black transition zone; the specific performance characterization is shown in Table 1.

[0055] Table 1 performance parameter comparison table

[0056]

[0057] It can be seen from the comparative analysis that the aluminum iron interface bonding of the 316L honeycomb filled circular tube thin wall structure reinforced aluminum matrix composite prepared by vacuum gravity filling is better than that of the sample prepared by the die casting process; the aluminum iron interface of the 316L honeycomb filled circular tube thin wall structure reinforced aluminum matrix composite prepared by the die casting process has obvious black oxide layer, and part of the structure pores is not filled, and part of the structure is damaged during the die casting process; the hardness of the Al / Fe bonding area and the aluminum matrix of the sample prepared by the method is higher than that of the sample prepared by the die casting process, and the whole preparation process of the die casting composite material is long and more complicated, and the operation process is more dangerous.

Claims

1. A method for producing an iron-based honeycomb-filled round pipe thin-walled structure reinforced aluminum-based composite material, characterized by, The filling matrix material is aluminum ingot, and the method comprises the following steps: (1) calculating the required mass of aluminum ingot according to the volume of the filling hole and the density of the aluminum ingot; (2) Put the iron-based honeycomb filled circular tube thin wall structure and aluminum ingot stack into a corundum ceramic boat, with the aluminum ingot above the thin wall structure, place the corundum ceramic boat in a high-temperature resistant glass tube, use a vacuum pump to vacuumize the two, wherein the vacuum degree is 10 -1 ~10 - 4 Pa, and then use oxyhydrogen welding to seal the tube; (3) placing the glass tube in a sintering furnace for sintering, cooling to room temperature after sintering is completed, and then taking out the sample, thereby obtaining the iron-based honeycomb filling round tube thin-walled structure reinforced aluminum matrix composite material; The sintering condition is 800-1000 DEG C, and the holding time is 100-300 min.

2. The method for preparing the iron-based honeycomb-filled thin-walled circular tube reinforced aluminum-based composite material according to claim 1, characterized in that: The mass of the aluminum ingot in step (1) is 1.3-1.75 times the calculated mass.

3. The iron-based honeycomb filling round tube thin-walled structure reinforced aluminum matrix composite material prepared by the preparation method according to any one of claims 1-2.

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