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Casting aluminum alloy classification
Source: | Author:佚名 | Published time: 2022-01-18 | 407 Views | Share:

According to the difference of main alloying elements, there are four types of cast aluminum alloys.

(1) Aluminum-silicon alloys, also called "silicon-aluminum-ming" or "silicon-aluminum-ming". It has good casting performance and wear resistance, and has a small thermal expansion coefficient. Among the cast aluminum alloys, there are the most varieties and the largest amount of alloys, and the silicon content is 4% to 13%. Sometimes silicon-aluminum alloys with 0.2% to 0.6% magnesium are added, which are widely used in structural parts, such as shells, cylinders, boxes and frames. Sometimes adding an appropriate amount of copper and magnesium can improve the mechanical properties and heat resistance of the alloy. Such alloys are widely used to make components such as pistons.

(2) Aluminum-copper alloy, the alloy containing 4.5% to 5.3% copper has the best strengthening effect. Appropriate addition of manganese and titanium can significantly improve the room temperature, high temperature strength and casting performance. It is mainly used to make sand castings with large dynamic and static loads and uncomplicated shapes.

(3) Aluminum-magnesium alloy, a cast aluminum alloy with the smallest density (2.55g/cm3) and the highest strength (about 355MPa), containing 12% magnesium, with the best strengthening effect. The alloy has good corrosion resistance in the atmosphere and seawater, and has good comprehensive mechanical properties and machinability at room temperature. It can be used for radar bases, aircraft engine cases, propellers, landing gear and other parts, as well as decorative materials.

(4) Aluminum-zinc alloys are often added with silicon and magnesium elements in order to improve their properties, which are often called "zinc-silicon-aluminum-ming". In the casting condition, the alloy has a quenching effect, that is, "self-quenching". It can be used without heat treatment. After heat treatment, the casting has higher strength. After stabilization treatment, the size is stable, and it is often used to make models, templates and equipment brackets.

Cast aluminum alloys have the same alloy system as wrought aluminum alloys, and have the same strengthening mechanism as wrought aluminum alloys (except for strain strengthening). Their main difference is that the maximum content of alloying element silicon in cast aluminum alloys exceeds that of most deformed aluminum alloys. Silicon content in aluminum alloys. In addition to strengthening elements, cast aluminum alloys must also contain a sufficient amount of eutectic elements (usually silicon) to make the alloy have considerable fluidity and easily fill the shrinkage joints of the casting during casting. At present, there are only the following 6 basic alloys;

① AI-Cu alloy, ② AI-Cu-Si alloy ③ AI-Si alloy, ④ AI-Mg alloy, ⑤ AI-Zn-Mg alloy, ⑥ AI-Sn alloy.