Preparation process of high volume fraction silicon particle enhanced aluminum based composite material

Abstract

The invention relates to a preparation process of a high volume fraction silicon particle enhanced aluminum based composite material, which is characterized by comprising the step of: preparing a completely-compacted Si / Al composite material large-size billet with Si granules of 50vol.percent to 80vol.percent and thin and uniform texture by using a flexible and practical powder metallurgy process. The prepared composite material has excellent combination property. The preparation process comprises the steps of: uniformly mixing prealloy aluminum powder with pure silicon powder in a mass ratio of 1:(0.86-2.1) to prepare composite powder; carrying out cold moulding on the composite powder, wherein a relative compactness of a cold moulding blank is 50-80 percent; compacting the cold moulding blank at a temperature slightly higher than the temperature of a matrix alloy solidus curve to prepare a completely-compacted billet; and processing a thermally-pressed billet into a stand column or billets with other shapes by adopting methods, such as turning, spark cutting and the like for preparing for transportation and performance tests or further machining.

Description

technical field [0001] The invention relates to the technical field of particle-reinforced metal-matrix composite materials; in particular, it relates to a preparation process of high-volume silicon particle-reinforced aluminum-matrix composite materials. Background technique [0002] Particle-reinforced aluminum matrix composites have excellent comprehensive properties such as high specific strength, high specific stiffness, low expansion, high thermal conductivity, fatigue resistance, isotropy, etc., and the cost of particle reinforcement is low, and the manufacturing process is simple and cheap. After the past 30 years of development, this type of material has been widely used in aerospace, automotive and microelectronics, and is expected to become another new type of structural material after aluminum alloy and titanium alloy. The density of silicon (2.33g / cm 3 ) is 14% lower than aluminum alloy. It has extremely low expansion coefficient, high thermal conductivity, hig...

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Problems solved by technology

[0004] High-volume silicon particle-reinforced composite materials are mainly prepared by liquid phase impregnation method (200410043855, 200510024032) and spray deposition method (200410039057). Although the liquid phase method can produce dense and uniform composite parts, due to the excessive particle size Large (50-150μm), resulting in poor mechanical properties and machining properties of the material; at the same time, because silicon can be solid-soluble in aluminum, it is difficult to control the particle size and morphology and the interface of the composite material in the liquid phase environment

However, the high-volume Si / Al prepared by spray deposition method is not dense, and large-size ingots cannot be produced

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