Investment molded precision casting parts

The material and thickness of the investment casting of agricultural machinery is the length of the maintained pressure. For high melting point, crystallization temperature range, thick-walled castings, the pressure duration is longer. For the crystallization temperature range is small and the wall is thin casting parts, holding pressure time can be shorter. If the holding time is not enough, Shanghai precision castings are prone to casting defects. But hold pressure time is too long, precision cast steel parts can not play a great practical effect, easy to cause vertical aluminum die-casting machine to remove the edge of the remaining material difficult. From the shape memory alloy add filling concave mold to the inner inlet glue mouth completely solidified, again under the action of the pressure injection punch time delay called holding time. The role of the pressure duration of the investment casting valve body is to give the pressure needle enough time to transfer the working pressure to the solidified metal material to ensure that the casting crystallizes under the working pressure to improve shrinkage in order to obtain high-density tissue. In aluminum die casting, the time necessary for the shape memory alloy to fill the die from the start of its entry into the die is called the charging time. The length of the additive charge time depends on the capacity specifications and complexity of the precision casting. For large and simple products, the charging time should be relatively long, and for complex and thin-walled casting parts, the charging time should be longer. The adjustment method of charging time is similar to the adjustment method of charging speed.