The role of silicon in low pressure aluminum casting

One way is to add silicon in the aluminum alloy die casting to improve the flow of the alloy. In fact, this way is all-round, there are errors frauds. Let's understand the key effect of adding silicon to the alloy!

1. Adding silicon can improve the fluidity. This effect is mainly used for filling under low gas pressure such as aluminum alloy casting. As a matter of fact, there is much difference in the processing factory of auto parts aluminum castings when silicon is added used to fill the alloy under the pressure of filling gas over 1MPa. Today's die casting process, filling gas pressure can exceed 100 MPa, the worst flow alloy is difficult enough to fill.

2. It can reduce the shrinkage of phase transformation volume of "liquid-solid" phase. According to many experiments, the aluminum alloy with silicon content up to 20% can achieve the transformation volume basically unchanged. Therefore, if the aluminum piston rod is used in the high temperature place, it will generally be the alloy with higher silicon content. Due to the essential characteristics of the die casting process, it belongs to the single direction high pressure filling forging, which does have the effect of opposite direction feeding. It is an area completely different the processing characteristics of low pressure casting aluminum alloy casting with opposite direction feeding. Because of this reason, the manufacturing industry is deliberately equipped with aluminum alloy models with low transformation shrinkage, the silicon content is as high as possible, so that the die casting process can be backfilled in the opposite direction.

The addition of silicon in the alloy has defects, which are accompanied by defects. The price is that the compressive strength of the alloy is greatly reduced, the tensile strength is also significantly reduced.