Al-30Si aluminum alloy containing Sr, B, Ti and Zr and preparation process thereof

Abstract

The invention discloses a Al-30Si aluminum alloy containing Sr, B, Ti and Zr and a preparation process thereof. The high-silicon aluminum alloy is prepared by pouring an aluminum alloy molten mass at 750 DEG C into a metal mold with 200 DEG C in an atmospheric environment. The Al-30Si mother alloy is prepared by the following steps: smelting industrial pure aluminum with the purity of higher than 99.8 Wt% and silicon metal with the purity of higher than 99.5 Wt% in a graphite crucible by using a well-type resistance furnace, keeping the temperature at 850 DEG C for 4 hours, carrying out refining and degassing on the alloy liquid with hexachloroethane at 750 DEG C, and keeping the temperature for 30 minutes. The elements Sr, B, Ti and Zr are alloyed by respectively adding Al-10Sr, Al-5Ti-1B, Al-10Zr and other alloys at 720 DEG C and keeping the temperature for 30 minutes. The aluminum-silicon alloy comprises the following chemical components: 0.03-0.09 Wt% of Sr, 0.01-0.05 Wt% of B, 0.05-0.25 Wt% of Ti, 0.03-0.09 Wt% of Zr, 30 Wt% Si and the balance of Al. The tensile strength of the alloy is 149.4-245.4 MPa, the hardness is 37.5-82.1 HBW, and the resistivity is 0.107-0.127 ohm m.

Description

technical field [0001] The invention relates to an Al-30Si aluminum alloy containing Sr, B, Ti and Zr and a preparation process thereof. Background technique [0002] Due to its high specific strength and hardness, low density, strong corrosion resistance and wear resistance, good high temperature performance, small linear expansion coefficient, strong thermal conductivity, and low cost, high-silicon Al-Si alloys are ideal for engine pistons, precision wear-resistant parts and Ideal material for electronic packages. However, high-silicon aluminum alloys show brittleness due to coarse primary silicon, and their applications are limited. Using a single modifier to modify the morphology, size and distribution of primary silicon or eutectic silicon can improve the performance of high-silicon aluminum alloys, but it is difficult to simultaneously improve the morphology and shape of primary silicon and eutectic silicon. size and distribution, it is also difficult to further im...

AI Technical Summary

Problems solved by technology

However, high-silicon aluminum alloys show brittleness due to coarse primary silicon, and their applications are limited.

Using a single modifier to modify the morphology, size and distribution of primary silicon or eutectic silicon can improve the performanc