As-cast high-toughness die-cast aluminum-silicon alloy and preparation method and application thereof

Abstract

The invention discloses an as-cast high-toughness die-cast aluminum-silicon alloy and a preparation method and an application thereof, wherein the as-cast high-toughness die-cast aluminum-silicon alloy comprises 8-11wt% of silicon, 0.4-0.8wt% of manganese, 0.1-0.4wt% of vanadium, 0.1-0.4wt% of zirconium, 0.01-0.04wt% of bismuth, not more than 0.2wt% of iron, not more than 0.1wt% of inevitable inclusions and the balance of aluminum. The aluminum-silicon alloy not only exhibits high toughness and good thermal crack resistance, but also has good fluidity. When the melt is die-casted, the structural defects caused by the die-cast process can be significantly reduced and avoided; and subsequent alloy heat treatment process can be avoided; the production cost can be reduced while the mechanicalproperties of aluminum-silicon alloy castings are improved significantly.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to as-cast high-toughness die-casting aluminum-silicon alloy and its preparation method and application. Background technique [0002] Light metal alloys such as aluminum alloys have attracted attention in recent years due to their high specific strength and specific stiffness, good shock absorption, thermal conductivity, machinability and recyclability. Among them, when the composition of the hypoeutectic Al-Si alloy is close to the eutectic point, as the amount of silicon increases, the crystallization temperature range becomes smaller, and the fluidity increases accordingly. Silicon has very little shrinkage, so the alloy is less prone to hot cracking. High-pressure casting is suitable for the production of thin-walled parts with complex shapes, and the die-casting process has a short molding cycle, high production efficiency, and environmental friendliness, and is wid...

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Problems solved by technology

However, in the high-pressure casting process, the low-speed and high-speed movement of the punch makes the molten metal turbulently entrained, and a large number of holes formed become an important reason for reducing the mechanical properties; moreover, due to the long residence time of the molten metal in the pressure chamber and the rapid filling A large shear force is generated, so special structures are formed in the alloy: pressure chamber pre-crystallized structure ESCs and defect band DBs, these structures reduce the mechanical properties

[0003] At present, although die-casting aluminum alloy die-casting parts have been successfully used in automobiles, communication electronics, aerospace and other fields, due to their low absolute strength, poor high-temperature mechanical properties and difficulty in subsequent heat treatment processes, die-casting aluminum alloys are mainly It is used to produce service parts that do not require high mechanical properties at room temperature, but it is still not applicable to structural parts that have high requirements for mechanical properties

In recent years, heat treatment improved high-vacuum die-casting aluminum alloy parts have been widely used. Although a suitable heat treatment process has greatly improved the performance of die-cast aluminum alloys, however, due to the deformation and bubbling of parts caused by heat treatment, further research is needed. machining, and heat treatment itself is an energy-consuming process, which increases the production cost of castings

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