Why the zinc alloy die casting parts have misrun over the surface There are many quality problems in the process of zinc alloy die casting. In the process of die-casting, some parts of the filling is incomplete, or even the shape does not meet the requirements of the customer drawings, known as under-casting or misrun. The filling condition is bad and the undercast part is kind of irregular condensed metal.When the pressure is insufficient, the liquid metal in the flow front solidifies prematurely, resulting in the location of the casting. At the same time, the mold temperature is too low, the pouring temperature is too low, the location of the internal gate is not good, the formation of flow resistance will also cause the casting undercasting. Improper coating materials or spraying methods will result in local coating deposition, leaving residues in the mold cavity, and thus causing casting defects. In the process of zinc alloy die casting, it is necessary to make a correct judgment of the quality problems, find out the root cause of the quality problems, and put forward feasible improvement measures to constantly improve the quality of the castings.