Purpose of gamma-Al2O3 nano particles in preparation of modified high-silicon aluminum alloy

Abstract

The invention belongs to the technical field of high-silicon aluminum alloys and particularly relates to a purpose of gamma-Al2O3 nano particles in preparation of a modified high-silicon aluminum alloy. The gamma-Al2O3 nano particles serve as a modificator, the usage amount of the modificator is 0.1 at. %-5.0 at. %, and the particle diameter is 20-50 nm; and the high-silicon aluminum alloy is composed of silicon and aluminum, the content of the silicon is 20 at. %-50 at. %, and the balance is aluminum. The gamma-Al2O3 nano particles are vibrated by means of ultrasound, the size of primary silicon becomes smaller, the morphology of the primary silicon is also converted from irregular, long-strip and five-disc star shapes into block shapes, eutectic silicon is also obviously refined, the shape of the eutectic silicon is converted into a short bar shape and a granulate shape from a long needle shape, both the primary silicon and the eutectic silicon achieve a modification effect, the strength and tenacity of the high-silicon aluminum alloy are improved greatly, and the high-silicon aluminum alloy is applicable to large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of modification of high-silicon aluminum alloys, in particular to γ-Al 2 o 3 The use of nano particles in the preparation of modified high-silicon aluminum alloys. Background technique [0002] As an important lightweight metal structure material, high-silicon aluminum alloy has a series of excellent properties such as small specific gravity, high specific strength, low thermal expansion coefficient, good dimensional stability, wear resistance, and corrosion resistance. The improvement of the density of the alloy, the reduction of the thermal expansion coefficient, and the improvement of processing and casting properties, so high-silicon aluminum alloys are especially suitable for the manufacture of lightweight, wear-resistant structural parts, in aviation, aerospace, automotive industry, shipbuilding and electronic packaging and other fields have broad application prospects. [0003] At present, the rese...

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Problems solved by technology

However, there are many defects in chemical modification. First, the interaction between modified elements will weaken the modification effect of high-silicon aluminum alloys. For example, Sr and P generate Sr at high temperature. 3 P 2 , secondly, as the addition of P-containing master alloy increases, the refinement effect of the primary silicon phase will tend to be saturated, and even over-modification will occur. The essence of high-silicon aluminum alloy modification is to control the nucleation of silicon crystals. and growth process to tune the size and morphology of silicon crystals

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