2, hexin precision casting when solid-liquid two-phase area wide called volume solidification mode.Belong to the volume of solidification of alloy ductile iron, high carbon steel, bronze, aluminum, copper alloy, aluminium magnesium alloy, magnesium alloy, lead bronze, and some brass, etc.Generally think of solidification of alloy filling volume shrinkage is poorer, prone to cracking, is difficult to obtain tissue density of castings.3, hexing precision casting solid liquid two phase zone width in between is called solidification mode in the middle.If the alloy crystallization temperature range is relatively narrow, section temperature difference is bigger, or casting solidification on the casting section width between layered coagulation, and volume of the region, belong to the middle way of solidification.