Anti shrinkage process measures for hardware precision casting manufacturers

Anti shrinkage process measures for hardware precision casting manufacturers

In the production process of precision casting, shrinkage and porosity reduce the effective area of the casting under stress, and stress concentration is prone to occur in the hole area, leading to a decrease in the mechanical properties of the casting. Shrinkage and porosity also reduce the airtightness, physical and chemical properties of castings. When shrinkage and porosity are severe, castings have to be scrapped. Today, we will talk about the anti shrinkage process measures of hardware precision casting manufacturers.

During the condensation process of liquid alloys, if the volume reduced by liquid shrinkage and solidification shrinkage is not replenished, some pores are formed in the final solidification area of the casting. The large and concentrated ones are called keyholes, while the small and scattered ones are called shrinkage holes. The fundamental measure to prevent shrinkage in castings is to use directional solidification. The process of gradually solidifying a casting in a specified direction from one part to another. In the order of directional solidification, the shrinkage of the solidification area is first supplemented by the molten metal in the later solidification area; The shrinkage of the post solidification area is supplemented by the metal liquid from the riser or pouring system, so that the shrinkage of each part of the casting can be supplemented, and the shrinkage cavity is transferred to the excess part of the riser or pouring system of the casting.

Precision machining