Airblast Steel Abrasives
Hardness / ToughnessThe degree of hardness required is determined by the speed of clean required, the type of contaminant to be removed, the surface finish and profile required and the operational costs involved. Abrasive hardness is important because hard- ness, by definition, is resistance to deformation. So the harder the pellet, the less it deforms and the more it performs useful work in deforming the work surface. However, energy is wasted in the fracturing of pellets so there is no advantage in using an abrasive which is hard, but also extremely brittle. Maximum hardness combined with a low breakdown rate is required for optimum results. Abrasive hardness correlates directly with cleaning speed in that the harder the abrasive, the faster it cleans.
Hardness is also an important factor in cleaning quality, particularly when the work is intricate and has deep cavities. The harder the abrasive shot, consistent with lack of brittleness, the greater its ability to ricochet. Areas of parts that cannot be cleaned by the direct blast depend on rebounding abrasive for adequate cleaning. Abrasive hardness, therefore, is an important factor in cleaning economy because it determines the length of cleaning cycles and the quality of the resulting finish.