TiB2 reinforced high-modulus Al-Si-Ni-Fe alloy and preparation method and application thereof

Abstract

The invention provides a TiB2-reinforced high-modulus Al-Si-Ni-Fe alloy and a preparation method and application thereof.In the TiB2-reinforced high-modulus Al-Si-Ni-Fe alloy, the mass fraction of Si is 7.5 wt.%-9.5 wt.%, the mass fraction of Ni is 0.1 wt.%-0.5 wt.%, the mass fraction of Al is 0.1 wt.%-0.5 wt.%, and the mass fraction of Al The mass fraction of the Fe element is 0.7 wt.%-0.9 wt.%; the mass fraction of the Ni element is 0.8 wt.%-2.1 wt.%; the mass fraction of TiB2 is 1.8 wt.%-4.2 wt.%; and the balance of Al. The invention further discloses a preparation method of the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy. The elastic modulus of the TiB2 reinforced high-modulus Al-Si-Ni-Fe alloy reaches up to 83 Gpa, the high-standard requirement of the market for the elastic modulus of the Al alloy can be met, and the TiB2 reinforced high-modulus Al-Si-Ni-Fe alloy has very good application prospects and large-scale industrial popularization potential in the fields of engines and compressors.

Description

Technical Field

[0001] The invention relates to aluminum alloy technology, and in particular to a TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, a preparation method and use thereof. Background Art

[0002] Due to their low density and excellent wear resistance, Al-Si alloys have become an ideal alternative to traditional cast iron and cast steel in the manufacture of engine and compressor wear parts. Faced with increasing CO2 emissions and rising fuel costs, the automotive industry is committed to producing lighter, stronger and more environmentally friendly vehicles by adopting lightweight alloys. Currently, the industry is looking for ways to significantly reduce the weight of aluminum-based structural parts, among which Young's modulus and yield strength are key design parameters. High Young's modulus helps to reduce wall thickness and thus reduce the material volume of the component. However, the relatively low Young's modulus of Al-Si alloys limits their application range.

[0003] For example, the Young's modulus of the common commercial cast Al-Si alloy on the market is about 70GPa. This relatively low value often leads to an increase in the wall thickness of the structural parts, which in turn increases the weight, weakening the weight reduction advantage pursued by the Al alloy in the application. Summary of the invention

[0004] The purpose of the present invention is to propose a TiB2 reinforced high modulus Al-Si-Ni-Fe alloy to address the problem of insufficient elastic modulus of the current Al-Si alloy. The elastic modulus of the alloy is as high as 82-86Gpa, which can meet the market's high standards for the elastic modulus of Al alloys and has very good application prospects and large-scale industrial promotion potential in the fields of engines and compressors.

[0005] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, wherein the mass fraction of Si element is 7.5wt.%-9.5wt.%; the mass fraction of Fe element is 0.7wt.%-0.9wt.%; the mass fraction of Ni element is 0.8wt.%-2.1wt.%; the mass fraction of TiB2 is 1.8wt.%-4.2wt.%; and the balance is Al.

[0007] Furthermore, the preferred alloy has a Si element mass fraction of 8.4-9.5wt.%; a Fe element mass fraction of 0.7-0.9wt.%; a Ni element mass fraction of 1.4-1.7wt.%; and a TiB2 mass fraction of 3.8-4.2wt.%.

[0008] Furthermore, the more preferred alloy has a Si element mass fraction of 9wt.%; a Fe element mass fraction of 0.8wt.%; a Ni element mass fraction of 1.6wt.%; and a TiB2 mass fraction of 4wt.%.

[0009] Furthermore, in the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, titanium and boron form a TiB2 intermediate phase, which exists in the form of particles with a particle size of 200nm-1μm. In the present invention, the average size of the TiB2 particles is 227.9nm.

[0010] Furthermore, the elastic modulus of the Al alloy is increased by 3-12% relative to that of the matrix (Alloy 1), reaching up to 82-86 GPa.

[0011] Another object of the present invention is to disclose a method for preparing a TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, comprising the following steps:

[0012] Step 1. Raw material preparation;

[0013] Step 2. Preheating: put the mold into a 230-270℃ constant temperature box for preheating;

[0014] Step 3. Melting: pure aluminum, pure Cu, Al-6wt.% TiB2 precursor, Al-10Ni master alloy, and Al-10Fe master alloy are placed in a crucible together, and melted and heated to 750-780° C. in a pit-type melting resistance furnace, and high-purity argon gas is introduced to degas the melt for 5-10 minutes to obtain a melt, and an auxiliary process is used to completely melt the melt;

[0015] Step 4. Casting: pour the melt into a preheated mold at a pouring temperature of 710-730°C to obtain an ingot.

[0016] Furthermore, the raw materials of step 1 are: pure aluminum (purity 99.999%), pure Si, pure Cu, Al-10Fe master alloy, Al-10Ni master alloy and Al-6wt.%TiB2 precursor.

[0017] Furthermore, the crucible in step 3 is a graphite clay crucible.

[0018] Furthermore, the smelting in step 3 is heated to 750-770°C.

[0019] Furthermore, the auxiliary process in step 3 is electromagnetic stirring.

[0020] Furthermore, the auxiliary process treatment time in step 3 is 3-5 minutes.

[0021] Furthermore, in the Al-6wt.%TiB2 precursor, the molar ratio of titanium (Ti) to boron (B) is 2.1.

[0022] Another object of the present invention is to disclose a TiB2 reinforced high modulus Al-Si-Ni-Fe alloy for use in the field of engines and compressors.

[0023] The TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, the preparation method and the use thereof of the present invention have the following advantages compared with the prior art:

[0024] 1) TiB2 is added to the alloy of the present invention. As a ceramic phase for casting, TiB2 has an extremely high Young's modulus (E=565GPa). Only 9 volume percent of TiB2 is needed to significantly improve the specific stiffness E / ρ of the aluminum alloy by more than 30%. In addition, TiB2 nanoparticles can also significantly enhance the Orowan strengthening mechanism, further improving the material performance. At the same time, by adding Ni elements to modify the iron-rich phase in the alloy, not only the elastic modulus can be improved, but also the overall strength of the material can be enhanced. The regulated iron-rich phase can increase the elastic modulus of the material by 1.8%-5.1% compared to the matrix, and after adding TiB2 particles, the elastic modulus of the material can be increased by 6.4%-9% compared to the matrix, meeting the current market's high standards for the elastic modulus of Al alloys.

[0025] 2) The preparation method of the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy of the present invention has a simple process and the required raw materials are easy to obtain, which not only simplifies the production process but also reduces costs, making the commercial production of this high-performance alloy possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the metallographic structure of Al-Si-Ni-Fe alloy, where: (a) is alloy 1, (b) is alloy 2, (c) is alloy 3, and (d) is alloy 4;

[0027] Figure 2 Schematic diagram of the metallographic structure of TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, where: a and c are low-magnification images of alloy 5 and alloy 6, respectively; b and d are high-magnification images of alloy 5 and alloy 6, respectively;

[0028] Figure 3The modulus test results of Al-Si-Ni-Fe alloy;

[0029] Figure 4 The elastic modulus test results of Alloy 5 and Alloy 6. DETAILED DESCRIPTION

[0030] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0031] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0032] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0033] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0034] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0035] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0036] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0037] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0038] Comparative Examples 1-4

[0039] Comparative Examples 1-4 (Alloy 1-Alloy 4) disclose a variety of Al-Si-Ni-Fe alloys, which are prepared by the following method:

[0040] 1. Raw material preparation: pure aluminum (purity 99.999%); pure Si; pure Cu; Al-10Fe, Al-10Ni master alloys; Al-6wt.% TiB2 precursor (where Ti / B≈2.1, Ti and B elements mainly exist in the form of intermediate phase TiB2, TiB2 exists in the form of particles, and the average particle size is 227.9nm);

[0041] 2. Melting: Put pure aluminum, pure Si, pure Cu, Al-10Fe, and Al-10Ni master alloys into a crucible and place it in a resistance furnace to heat to 760°C, and introduce high-purity argon gas to degas the melt for 10 minutes. Finally, use an auxiliary process to treat the melt for 5 minutes to completely melt it;

[0042] 3. Casting: When the melt is cooled to 710-720℃, pour the melt into a preheated mold to obtain an ingot.

[0043] Embodiment 5-6

[0044] The present embodiments 5-6 (Alloy 5-Alloy 6) disclose two TiB2 particle reinforced high modulus Al-Si-Ni-Fe alloys, which are prepared by the following method:

[0045] 1. Raw material preparation: pure aluminum (purity 99.999%); pure Si; pure Cu; Al-10Fe, Al-10Ni master alloys; Al-6wt.% TiB2 precursor (where Ti / B≈2.1, Ti and B elements mainly exist in the form of intermediate phase TiB2, TiB2 exists in the form of particles, and the average particle size is 227.9nm);

[0046] 2. Melting: put pure aluminum, pure Si, pure Cu, Al-10Fe, Al-10Ni master alloy, Al-6wt.%TiB2 precursor into a crucible and place it in a resistance furnace to heat to 760°C, and introduce high-purity argon gas to degas the melt for 10 minutes, and finally use auxiliary process to treat the melt for 5 minutes to make it completely melted;

[0047] 3. Casting: When the melt is cooled to 710-720℃, pour the melt into a preheated mold to obtain an ingot.

[0048] The components included in Comparative Examples 1-4 and Examples 5-6 are shown in Table 1.

[0049] Table 1. Chemical element composition of each alloy (wt.%)

[0050]

[0051] After adding TiB2 to Alloy 5 and Alloy 6, the percentages of Si, Fe and Ni increased slightly, which was due to the error in the data when Xrf measured the Si content.

[0052] Figure 1 The metallographic diagrams of the alloys are shown in Figure 1. As can be seen from the figure, with the increase of Ni in the alloy, the iron-rich phase in the alloy improves, gradually transforming from β-Fe phase (160GPa) to α-Al(FeNi)Si phase (180-190GPa);

[0053] Figure 2 The metallographic diagrams of Alloy 3 with 2wt.% TiB2 (Alloy 5) and 4wt.% TiB2 (Alloy 6) added respectively. The presence of TiB2 particles increases the elastic modulus of the material.

[0054] Figure 3 is the elastic modulus test result of each alloy. With the increase of Ni content, the elastic modulus of the alloy increases from 76.1GPa to 80GPa;

[0055] Figure 4 The elastic modulus test results of alloy 3 with addition of 2wt.% TiB2 and 4wt.% TiB2 show that the elastic modulus increases from 78.5GPa to 83GPa.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A TiB2 reinforced high modulus Al-Si-Ni-Fe alloy, characterized in that: in, The mass fraction of Si element is 7.5wt.%-9.5wt.%; the mass fraction of Fe element is 0.7wt.%-0.9wt.%; the mass fraction of Ni element is 0.8wt.%-2.1wt.%; the mass fraction of TiB2 is 1.8wt.%-4.2wt.%; and the balance is Al.

2. The TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 1, characterized in that: Titanium and boron form a TiB2 intermediate phase, which exists in the form of particles with a particle size of 200nm–1μm.

3. A method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 1 or 2, characterized in that: The following steps are involved: Step 1. Raw material preparation; Step 2. Preheating: put the mold into a 230-270℃ constant temperature box for preheating; Step 3. Melting: pure aluminum, pure Cu, Al-6wt.% TiB2 precursor, Al-10Ni master alloy, and Al-10Fe master alloy are placed in a crucible together, and melted and heated to 750-780° C. in a pit-type melting resistance furnace, and high-purity argon gas is introduced to degas the melt for 5-10 minutes to obtain a melt, and an auxiliary process is used to completely melt the melt; Step 4. Casting: pour the melt into a preheated mold at a pouring temperature of 710-730°C to obtain an ingot.

4. The method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 3, characterized in that: The crucible in step 3 is a graphite clay crucible.

5. The method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 3, characterized in that: The smelting is heated to 750-770°C in step 3.

6. The method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 3, characterized in that: The auxiliary process in step 3 is electromagnetic stirring.

7. The method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 3, characterized in that: The auxiliary process treatment time in step 3 is 3-5 minutes.

8. The method for preparing the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 3, characterized in that: In the Al-6wt.%TiB2 precursor, the molar ratio of titanium to boron is between 1.8 and 2.

5.

9. Use of the TiB2 reinforced high modulus Al-Si-Ni-Fe alloy according to claim 1 in the field of engines and compressors.

Images