Aluminum alloy gravity forging is to use the working pressure of gravity downward, with the help of a certain temperature gradient of abrasive tools, so that the casting can condense according to the setting setting setting benchmark, which is conducive to the instant filling of aluminum soup. With the help of machine equipment, the effective conception of abrasives, the effective control of the stoker the concrete pouring personnel, the ideal casting plant of Zhejiang Hangzhou low-pressure Aluminum Casting Co., Ltd. can be made. Theoretical gravity forging includes sand mold forging, metal mold forging, investment mold forging, EPC forging, mud mold forging, etc.; aluminum alloy gravity forging refers to metal mold forging. Because of its low melting point strong forging property, aluminum alloy gravity forging parts high-pressure forging goods are widely used in the trolley Hangzhou low-pressure aluminum casting processing plant, motorcycles, mechanical electrical engineering, communications, hardware other aspects, especially in the transportation of large wall thickness goods, there are many problems solutions of auto parts aluminum casting.
In foreign countries, aluminum alloy forging methods include metal mold forging vacuum pump high pressure forging. In China, because of the perfect processing technology short preparation period, most aluminum alloy forging units adopt metal gravity forging. The gravity forging of aluminum alloy metal mold is a forging process using the net weight filling feeding of the liquid metal itself. The flow field is caused casually in the pouring filling steps of the liquid metal, which makes the liquid aluminum alloy easy to be entrained oxidized by air. Therefore, the incorrect errors such as pinhole, air hole assimilation are caused casually in the aluminum alloy casting. The gravity forging of aluminum alloy controls the working pressure of the molten metal in the riser to stop the feeding of the casting. The feeding effect is weak, the casting causes the defect of reduction at will.
Shrinkage porosity: this defect is often caused in the thick mold unit thin thick soil of the casting. It is assumed that the white surface of the casting is the main manifestation of shrinkage porosity.
The causes of shrinkage are as follows:
1. In the gravity forging process of aluminum alloy, due to the reduction of its initiation, liquid metal can be obtained to pay off the vent caused by debt.
2. The pouring temperature is too high, the mold temperature coefficient is unreasonable;
3. The inner rubber inlet is relatively thin, the total area is very small, premature condensation, unlucky working pressure announcement liquid metal feeding.
4. The casting administrative organ has the hot spot position the cross section changes violently.