Squeeze casting Al-Si-Cu alloy material

Abstract

The invention relates to an aluminum alloy material, in particular to an extrusion casting Al-Si-Cu alloy prepared by solution heat treatment (T4 heat treatment) and solution heat treatment plus full artificial aging (T6 heat treatment) processes; the main components and the mass percentage thereof are as follows: 5.30 percent to 6.20 percent of silicon, 3.80 percent to 4.30 percent of copper, 0.60 percent to 0.91 percent of trace alloy strengthened element, 0.20 percent to 0.30 percent of impurity element iron, and the rest are aluminum and inevitable trace impurities. The material not only has quite high strength and good plasticity, but also has good casting shaping performance, low raw material cost and convenient sources, is in particular applicable in manufacturing parts with light weight and less weight requirements, and has very broad application prospect in automobile, aviation and other industries.

Description

technical field [0001] The invention relates to an aluminum alloy material, in particular to a squeeze-cast aluminum-silicon-copper alloy material with excellent mechanical properties and good casting formability. Background technique [0002] The lightweight of auto parts is one of the main ways to reduce the weight of automobiles and realize energy saving. It can be achieved both by using light metals and by using high-strength materials. The strengthening and toughening of aluminum alloys covers the above two aspects of the development of lightweight components, so it has received extensive attention. [0003] Aluminum alloys mainly include wrought aluminum alloys and cast aluminum alloys. Deformed aluminum alloys reduce defects, refine grains, and increase microstructure density through extrusion, rolling, drawing, forging, etc., so they have high strength and good toughness, and have been widely used. However, wrought aluminum alloys have high requirements on process...

AI Technical Summary

Problems solved by technology

[0006] 1) These alloys have a wide range of crystallization temperature and poor casting performance. The specific manifestations are serious segregation and thermal cracking tendency, poor fluidity, difficult feeding, and prone to defects such as shrinkage cavity and shrinkage porosity; at the same time, it is difficult to apply to rigid molds. In production, the sand casting process is mainly used to form the parts. The performance of the formed parts is far from that of the test rod. Compared with the rigid mold casting, the surface quality of the formed parts is not high and the dimensional accuracy is poor.

[0007] 2) In order to obtain good performance, the control of the content of impurity elements in the above alloys is very strict. For example, the A-U5GT alloy requires iron to be controlled below 0.1%, and the ZL205A alloy requires iron to be controlled below 0.15%. Therefore, raw materials need to be expensive. High-purity aluminum ingots, and the process control is difficult, the casting system and scrap castings are difficult to recycle, and the actual industrial application is difficult

[0008] 3) In order to obtain good performance, these alloys also need to add some precious alloying elements, such as the aluminum association grade 201.0 alloy (AlCu4AgMgMn) contains 0.40 to 1.00% silver, and the national standard ZL205A alloy contains cadmium and other precious metals, resulting in these alloy materials higher cost

[0009] 4) These alloys have high melting points, all of which exceed 630°C. In order to ensure the casting and forming, the melting temperature usually reaches 750°C. The alloy burns, oxidizes, absorbs gas seriously, and consumes a lot of energy. In addition, the liquid metal viscosity of these alloys reaches 0.4Pa. s, about 4 times that of Al-Si alloys, it is difficult to remove slag and degas during refining, and castings are prone to defects

However, the mechanical properties of this series of casting alloys are not high due to the lack of composition and preparation methods. Among them, the mechanical properties of ZL105A (4.50-5.50% Si, 1.00-1.50% Cu, 0.40-0.55% Mg, and the rest are Al) refer to the mechanical properties The highest, the tensile strength and elongation in the T5 state reach 290MPa and 2% respectively ("Foundry Engineer's Handbook", Mechanical Industry Press, 2001)

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