Comparison of Garnet for sandblasting and shot blasting

Garnet sand blasting and shot blasting are both commonly used methods for metal surface pretreatment. So what are the characteristics of both? Today we will compare Garnet sand blasting and shot blasting pretreatment.

1. Materials and equipment used

Garnet sand blasting is to use the sand blasting machine to hit the high-speed multi-angle Garnet sand abrasive on the surface of the workpiece, and form a certain roughness, improve the tension of the surface of the substrate, and increase its surface area. And it is conducive to the better combination of the subsequent coating and the workpiece, and prolongs the service life of the coating.

The principle of shot blasting is to use a motor to drive the impeller body to rotate (directly drive or drive with a V-belt), and rely on the action of centrifugal force to blast projectiles with a diameter of about 0.2 to 3.0mm (cast steel shot, steel wire cut shot, stainless steel shot, etc. Different types) are thrown to the surface of the workpiece to make the surface of the workpiece reach a certain roughness, make the workpiece beautiful, or change the welding tensile stress of the workpiece to compressive stress to improve the service life of the workpiece. By improving the roughness of the surface of the workpiece, the adhesion of the paint film of the subsequent painting of the workpiece is also improved.

The purpose of both is to achieve a certain roughness, improve the physical properties of the workpiece, and provide a better foundation for subsequent coating.

2. Comparison of the effect after treatment

After using Garnet sand blasting, the dirt on the surface of the workpiece is removed, the surface of the workpiece is slightly damaged, and the surface area is greatly increased, thereby increasing the bonding strength of the workpiece and the coating/plating layer. Moreover, the surface of the workpiece can restore the original color of the metal, and the most important thing is that the Garnet sand can penetrate into every corner and completely remove the dirt. Applicable metals are wider.

After shot peening, the dirt on the surface of the workpiece is removed, the surface of the workpiece is not damaged, and the surface area is increased. Since the surface of the workpiece is not damaged during the processing, the excess energy generated during processing will lead to the surface strengthening of the workpiece matrix. However, shot peening will have dead ends, so it is suitable for batch processing of workpieces with a single shape and surface.