Lanthanum-hexaboride-reinforced aluminum-silicon-base composite material and preparation method thereof

Abstract

The invention belongs to the field of metal materials, and relates to a lanthanum-hexaboride-reinforced aluminum-silicon-base composite material and a preparation method thereof. The composite material is composed of a matrix alloy and a reinforcing phase. The invention is characterized in that the matrix alloy contains a lanthanum hexaboride reinforcing phase which is dispersively distributed; and the composite material comprises the following components in percentage by mass: 5.00-20.00% of silicon, 0.68-6.82% of lanthanum, 0.32-3.18% of boron and the balance of aluminum. The preparation method comprises the following steps: melting technically pure aluminum, industrial crystalline silicon and aluminum-boron alloy in a smelting furnace according to certain mass ratio, heating to 800-1200 DEG C, keeping the temperature for 5-10 minutes, adding a proper amount of technically pure lanthanum into the melt, carrying out in-situ reaction for 10-15 minutes, refining, and casting, thereby obtaining the lanthanum-hexaboride-particle-reinforced aluminum-silicon-base composite material. The invention can be implemented by a common smelting technique under atmospheric conditions, has the advantages of no pollution, low cost, simple technique and high production efficiency, and is suitable for large-scale production and application.

Description

technical field [0001] The invention belongs to the field of metal materials, in particular to an aluminum-silicon-based composite material reinforced by lanthanum hexaboride and a preparation method thereof. Background technique [0002] Because of its excellent casting properties, such as small shrinkage, high fluidity, good air tightness and small thermal cracking tendency, aluminum-silicon alloy also has good mechanical properties, physical properties and cutting properties after modification. Therefore, it has a wide range of applications in aerospace, automobile industry and other fields. However, the need for energy saving and emission reduction drives the aluminum alloy material to develop in the direction of high specific strength, high specific stiffness, high temperature resistance, and fatigue resistance. Particle-reinforced metal matrix composites can combine the advantages of the matrix alloy and the reinforcing phase to improve the performance of the material...

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Problems solved by technology

[0003] At present, there have been many reports on the research on particle-reinforced Al-Si matrix composites at home and abroad, such as [Banqiu Wu, Ramana G.Reddy. In-situ formation of SiC-reinforced Al-Si alloy composites using Methane gas mixtures.Metallurgical and Materials Transaction B.2002, 33(4):543-550] reported a silicon carbide particle-reinforced aluminum-silicon matrix composite material and its preparation method, but the process is extremely complicated and the reaction process is difficult to control, which is not conducive to large-scale production; The Chinese patent No. 99114272.1 reports a titanium carbide-enhanced wear-resistant aluminum alloy and its preparation process, but TiC particles are extremely unstable in silicon-containing aluminum melts and are easily decomposed into Al 4 C 3 , thus affecting its strengthening effect on the matrix alloy; the literature [Yanfeng Han, Xiangfa Liu, Xiufang Bian.In-situ TiB2particulate reinforced near eutectic Al-Si alloy composites.Composites: Part A 2002, 33:439-444] reported a TiB 2 Particle-reinforced aluminum-silicon matrix composite material and its preparation method, TiB in the alloy 2 Particles have a serious tendency to aggregate, which restricts its application in industrial production