Shot blasting refers to a metal finishing process used primarily for surface preparation. It is a post finishing technique carried out by imparting the part surface using certain abrasive materials for preparing its surface. Compared to other methods, shot blasting can help in the preparation of the surface of the part to produce a much higher quality finish. It can provide an exceptional level of surface cleaning than any other finishing methods used.
Most die casting companies uses shot blasting for surface preparation before the part is subjected to other operations like electroplating, galvanizing, welding, enameling, glass coating, and rubberizing. In shot blasting, several abrasive materials are used to rapidly affect the surface of the part such as acrylic, aluminum oxide, corn cob, crushed glass grit, glass beads, etc. Its applications include improving the metal’s fatigue life, cosmetic finish, increased adhesion, improved mechanical function, and descaling of the product surface.
Shot blasting has several benefits for aluminum die casting since it is used mainly in the aerospace and shipbuilding industries. Shot blasting can cause an increase in the surface area of the part due to the raising of the roughness. It can eliminate surface dirt better that will significantly improve the adhesion properties of the surface. This will further increase by painting the surface or other methods. Surface stress concentration is something that happens in die cast parts due to the uneven rate of the cooling process and wall thickness.
The part, when subjected to shot blasting, can enhance the surface structure of the part and remove any prevailing surface stress concentration. This will also aid in enhancing the overall fatigue strength and the surface hardness of the part. By undergoing shot blasting treatment, the general character of the part can be restored and eliminating any attachments on the surface such as stains, scratches, thing edges, etc.
Another great benefit of shot blasting in die casting aluminum parts is that it can considerably enhance the overall cosmetic appearance. During shot blasting, the impact of the projectile will leave a small concave hole that can improve the reflectivity of the surface. This reflectivity is further increased if the part is then subsequently coated with paint or other components.
Shot blasting can considerably improve the durability and longevity of the part, which is a vital requirement for use in moving parts. It is a much simpler process and thereby adopted by many die casters in Mexico and the US because it prepares the part for the next process, which helps in eliminating the other processes like liquid sand blasting and use of drying equipment.