A high-strength wear-resistant die-casting aluminum alloy and its die-casting method

Abstract

The invention provides high-strength wear-resisting die-cast aluminum alloy and a die casting method for the same. The high-strength wear-resisting die-cast aluminum alloy comprises the following ingredients in percentage by mass: 10.6% to 11.4% of Si, 2.1% to 2.4% of Cu, 0.6% to 0.8% of Fe, 0.1% to 0.3% of Ti, 0.03% to 0.05% of Tc, 0.006% to 0.01% of B, 0.04% to 0.06% of Ba, 0.02% to 0.03% of Geand the balance of Al and inevitable impurities. The die casting method comprises the following steps: preparing materials; smelting aluminum alloy liquid; refining; degassing; deslagging; adding a grain refiner, a Fe-enriched phase and a Si phase modifier; stiring; and performing die-casting formation. Based on optimization of main alloy elements including Si and Cu, the die casting method provided by the invention adopts microalloying treatment to refine a modified Fe-enriched phase, an eutectic Si phase and a primary Si phase and improve the strength, plasticity and wear resistance of the die-cast aluminum alloy. The die-cast aluminum alloy provided by the invention is applicable to die-casting formation of various aluminum alloy parts and components having relatively high requirementson strength, plasticity and wear resistance.

Description

technical field [0001] The invention belongs to the field of aluminum alloy die-casting, and in particular relates to a high-strength wear-resistant die-casting aluminum alloy and a die-casting method thereof. Background technique [0002] Al-Si-Cu die-casting aluminum alloy belongs to hypereutectic aluminum-silicon alloy. Due to the high content of Si, it has excellent die-casting fluidity, wear resistance and machinability, and also has good air tightness, resistance Thermal cracking and low thermal expansion coefficient, therefore, Al-Si-Cu series die-casting aluminum alloys are widely used in automobiles, motorcycles, agricultural machinery, 3C products, electric tools, sewing machines, elevators and other fields that require high wear resistance and Aluminum alloy parts with complex shapes and structures, such as engine block, cylinder liner, piston, brake block, pulley, gear pump bearing and other parts. With the development of light weight and intelligence in transpo...

AI Technical Summary

Problems solved by technology

Although the existing Al-Si-Cu die-casting aluminum alloys have excellent die-casting fluidity, wear resistance and machinability, the problems of low strength and poor shaping have become increasingly prominent, which greatly limits the Al-Si-Cu die-casting aluminum alloy. Application of Si-Cu Series Die Casting Aluminum Alloy

[0003] The reason for the low strength and poor plasticity of the existing Al-Si-Cu die-casting aluminum alloys is that the die-casting aluminum alloys contain high Fe content, and Fe is usually in the form of thick needle-shaped Al-Fe-Si The Fe-rich phase exists in the aluminum alloy matrix. This coarse needle-like Fe-rich phase itself is a hard and brittle intermetallic compound phase, which will severely split the aluminum matrix and become the crack source and crack propagation direction of the aluminum alloy fracture.

Secondly, the Al-Si-Cu die-casting aluminum alloy belongs to the hypereutectic aluminum-silicon alloy. Due to the high content of Si, Si coexists in the form of acicular eutectic Si and coarse primary Si in the aluminum alloy. Crystalline Si and coarse primary Si are also hard and brittle phases, which will also severely split the aluminum matrix and reduce the strength, plasticity and wear resistance of aluminum alloys