Sandblasting is the process of cleaning and roughening the substrate surface by the impact of high-speed sand flow. Use compressed air as the power to form a high-speed jet beam to spray the blasting material (copper ore, quartz sand, corundum, iron sand, Hainan sand) at high speed on the surface of the workpiece to be processed, so that the appearance or shape of the outer surface of the workpiece surface changes. (1) Workpiece coating and sandblasting before workpiece bonding can remove all dirt such as rust on the surface of the workpiece, and establish a very important basic pattern on the surface of the workpiece (the so-called rough surface). By changing the abrasives with different particle sizes, the roughness of different degrees is achieved, which greatly improves the binding force of the workpiece with coatings and plating materials. Or make the adhesive bond more firm and better quality. (2) The rough surface of the casting, the cleaning and polishing of t...