As Cast Finishes

Zinc alloy diecastings are perfectly serviceable in the as cast condition for many applications.The appearance of the surface of a casting produced by a smooth die surface depends upon casting parameters such as die temperature, degree and type of lubrication, metal injection speed, and also on the “bloom” on the die surface. It is difficult therefore to control the surface appearance of the casting closely and some variability in as cast smooth surfaces is to be expected. This variability can be reduced using textured die surfaces produced by photoengraving the die. It has been shown that texturing not only hides small imperfections but also actually helps to prevent minor defects such as cold laps. In consequence it is probable that the appearance of an as cast zinc diecasting can be acceptable for most if not all “functional” components.