High-obdurability near-eutectic aluminum-silicon-copper-magnesium alloy and preparation method thereof

Abstract

The invention provides a high-obdurability near-eutectic aluminum-silicon-copper-magnesium alloy and a preparation method thereof. The alloy comprises the following elements of, by mass, 9-11% of Si,2.7-3.2% of Cu, 0.25-0.35% of Mg, 0.2-0.25% of Zr, 0.03-0.04% of Sr, 0.12-0.15% of Mm, larger than 0 and less than or equal to 0.2 % of Fe, larger than 0 and less than or equal to 0.2 % of Zn and thebalance Al. According to the method, through the preparation technology of step (1) raw material drying, step (2) melting, step (3) smelting, step (4) detecting, step (5) refining and step (6) casting, the alloy is obtained. According to the near-eutectic aluminum-silicon-copper-magnesium alloy, the mechanical property test result is that when the alloy is under the as cast condition, the room temperature tensile strength is 215-245 MPa, the fracture elongation rate is 2-3.5%, and the brinell hardness is 88-90; when the alloy is under the heat treatment state (T6), the room temperature tensilestrength is 410-440 MPa, the fracture elongation is 3.5-4.5 %, and the brinell hardness is 125-130; and the alloy can be used for preparing thin walls and complex castings, can be used for large andmedium castings which are capable of bearing major loads and are complex in shape, and can meet the service requirements of aviation and automobile important parts.

Description

technical field [0001] The invention belongs to the technical field of preparation of nonferrous metal materials, and in particular relates to a high-strength and toughness near-eutectic aluminum-silicon-copper-magnesium alloy material and a preparation method thereof. Background technique [0002] In aviation, automobile and other fields, many important parts (parts) bear various mechanical loads and thermal loads, and are in high temperature, high pressure, and high speed working conditions for a long time. Therefore, parts are required to have high mechanical properties at room temperature and high temperature, dimensional stability and resistance to harsh working conditions and environmental influences. [0003] The lightweight of aviation and automotive materials is the future development direction. Excellent structural materials should have high specific strength in order to meet the strength requirements with a small cross-section and greatly reduce the weight of part...

AI Technical Summary

Problems solved by technology

At present, the high-strength and toughness alloys used for high-performance casting in the prior art are near-eutectic aluminum-silicon alloys, and rare earth elements need to be used in the preparation, and the rare earth elements are scattered in the earth's crust, so it is difficult to extract and separate; the preparation process is complicated and the price is relatively high. high

The specific strength of the near-eutectic aluminum-silicon alloy in the prior art is not high enough, and the formability and toughness cannot meet the requirements for preparing parts with complex structures, thin walls and high toughness

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