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2020.12.28
Die-casting aluminum alloy has good usability and process performance, resulting in the rapid development of aluminum alloy die-casting. And cast aluminum alloys can be divided into Al-Si alloys, Al-Cu alloys, Al-Mg alloys and Al-Zn alloys and are based on what all the basic elements are of each alloy. In this guide, we detail each alloy’s features & properties, advantages and disadvantages.
1. A1-Si alloy
The characteristic of small crystals growth temperature difference, large solidification latent heat and large specific heat capacity in mother-of-alloys of silicon phase are not small. And its linear shrinkage coefficients in all of them is also relatively small. As mentioned earlier, the fact that the eutectic Al-Si alloy has the property of solving the thermal cracking and shrinkage problem. Its casting performance and filling ability is generally good when compared with other aluminum alloys makes it has better casting performances. The number of brittle phases (Silicon phases) that make up this alloy is the least amount, and the mass fraction is only about 10 percent, so its plasticity is better than other aluminum alloys. Layers of glass can be broken, and continue be made flexible, by changing the tough, brittle glass part. Engineering experiments show that the A1-Si eutectic binary alloy (specifically, grade AISI 416) still retains good plasticity when the temperature near its freezing point, and other alloys of aluminum (alloy grades AISI 400 and AISI 635) are unable to achieve the same performance. A considerable amount of eutectic is often required in the structure of casting alloys to ensure its good casting performance. The increase of the number of eutectic will make the alloy brittle and reduce the mechanical properties. In order to reconcile these two situations, something must be changed. Al-Si eutectic alloy (Al-Si alloy) has good plasticity, resulting in better meeting the requirements of both mechanical and casting performance. Al-Si alloy is currently the most widely used die-cast aluminum alloy.
Among the varieties of aluminum alloys that are used in China, the alloys of Al-si are the most predominant alloys. Unlike the basic methods, alloys may have low strength, insufficient cutting performance and be difficult in processing, forming threads As a result, stronger and more durable alloys have recently been developed in China.
2. Al-Zn alloy
Al-Zn alloy die castings can achieve a high degree of mechanical property after natural-aging, and may not require any mechanical restoration and aging treatments. When chain E is greater than 10 percent, you will find that chain E produces a significant increase in strength. This alloy contains some disadvantages such as poor corrosion resistance, stress corrosion phenomena and easy thermal cracking during die casting. The material commonly used to manufacture dentures is one that is an easy to fill cavity. The disadvantage of using this type of implant is that they form a porosity during use. When there is little silicon and iron, then the stones will be easily broken due to the expansion and contraction of the rock.
3. A1-Mg alloys
A1-Mg alloys have characteristics of good mechanical properties at room temperature, poor casting, great fluctuation in mechanical properties and wall thickness. But A1 Mg alloys are excellent in all of these aspects. The aging of alloys, such as that used for high-value carbon structural parts, will make them reduce their plasticity over time. Cracking will look like a strike on the parts that are manufactured. Most of the parts may be found to be more susceptible to stress corrosion cracking. The shortcomings of Al-Mg alloys, which include which includes its detrimental effects on redox reactions, make it applicable to certain degrees.
4. Die-cast aluminum alloys with special properties
Die-cast aluminum alloys with special properties developed at home and abroad are as follows:
Because of its texture and elongation, Al-Mn alloy acts as a good base compound for anodizing. Furthermore, it has great corrosion resistance. Their satisfactory cigarette smoking substitute have disadvantages of not high strength, high shrinkage rate and easily sticking to the mold. Heat-treating an alloy can be done in two ways: (1) heat-aging it to form “artificial artificial aging” and (2) artificially aging it to form “fully artificial aging.” It can be calculated. For surface treated Al-Mn-zns, Al-Si-, Cu- and Mn-alloys, stainless steel composite, extremely wear-resisting different hypereutectic Al-Si alloys, strong-endurance, explosion-proof and vibration-proof alloys are used. There are ceramics and aluminum alloy composite materials, which have not yet been widely produced and applied in hip and knee replacement.