The difference and characteristics of aluminum alloy pressure casting and gravity casting
Aluminum alloy is widely used in automobile manufacturing, furniture, shipbuilding, landscape and other fields due to its good plasticity, corrosion resistance and light weight. With the development of China’s manufacturing industry, the demand for aluminum alloy and aluminum alloy castings is increasing, which will also promote the development of the aluminum alloy casting industry. At present, the casting method of aluminum alloy is divided into two types: pressure casting and gravity casting. The casting order network will analyze the difference and characteristics of the two casting processes in detail.
Aluminum alloy casting processes are roughly divided into two types: gravity casting and pressure casting. Aluminum alloy pressure casting refers to the process of metal liquid in other external forces (excluding gravity) into the casting type, and pressure casting is divided into high pressure casting and low pressure casting. High-pressure casting is the die casting that we usually say. The aluminum liquid is poured into the pressure chamber, and the mold cavity is filled at a high speed by the pressure, and the aluminum liquid is solidified under pressure to form an aluminum casting.
The characteristics of aluminum alloy die castings are:
1. The surface finish of the product is good, generally up to Ra6.3 or even up to Ra1.6.
2, can not be heat treated.
3. The product has high air tightness, high casting strength and surface hardness, but low elongation.
4. The mold cost is high and the service life is short.
5. High production efficiency.
6, can produce thin-walled parts, processing allowance is small.
Aluminum alloy gravity casting refers to the process of aluminum liquid getting into mold type by manual, gravity casting is divided into: sand casting, metal (steel mold) casting, lost foam casting and so on.
At present, the most widely used metal mold (steel mold) casting, the mold is made of heat-resistant alloy steel. Cast aluminum castings strength, size, appearance, etc. are higher than other casting process castings.The gravity-cast aluminum liquid is generally poured into the gate by hand, and the sample is filled by the self-weight of the molten metal, exhausted, cooled, and opened to obtain a sample. The process is generally: aluminum liquid smelting, pouring filling, exhausting , cooling, mold opening, cleaning, heat treatment, processing.
The characteristics of aluminum alloy gravity castings are:
1. The surface finish of the product is not high, and it is easy to produce pits after shot blasting.
2. The aluminum casting has less internal pores and can be heat treated.
3. The product has low density and poor strength, but the elongation is high.
4. The mold cost is low and the mold has a long service life.
5. Low production efficiency, which increases production costs.
6, the process is relatively simple, not suitable for the production of thin-walled parts.When the product is selected for production.
The choice is mainly based on the wall thickness of the workpiece. When the wall thickness of the product is greater than 8 mm, the die casting will cause many pores to be stored in the wall. Therefore, the product with thicker wall thickness can be selected by gravity casting process.