Explanation

The solidification of casting is carried out along the length direction from the part away from the feeder to the feeder end. The purpose is to make all parts of the casting can be fed during solidification to prevent shrinkage hole or dispersed shrinkage of the casting. For complex castings, there may be more than one feeder and more than one progressive solidification direction. The fundamental principle of achieving sequential solidification is to maintain an appropriate temperature distribution during casting solidification. Therefore, the gating feeder system of castings should be reasonably designed, and the appropriate casting temperature, speed, chill, subsidy and other arrangements should be determined. progressive solidification is particularly suitable for alloy with large solidification shrinkage and narrow crystallization temperature range. Its disadvantage is that the internal stress and deformation of castings are large, and hot tear is easy to occur during solidification. Many measures should be taken to maintain the sequential solidification of castings, and molding and casting cleaning work have increased, thus increasing the cost.

Classification