Distinctive Properties of Diamond & Other Abrasive Grains

Diamond is the allotrope of carbon, its morphologies include octahedron, rhombic dodecahedron, cubic , etc. A minority of diamond is crystal or polymer. As the hardest substance in natural world, diamond Moh's hardness is 10, microhardness is 100Gpa.

Diamond hardness varies in different crystal face. Cubic octahedral (111Gpa) is the hardest, the second in hardness is rhombic dodecahedron (110Gpa), while cubic (100Gpa) is the least in hardness. Hardness vary in different directions on a same crystal face.

Diamond abradability is 140 times as much as that of corundum, 1000 times the hard alloy and 9000 times the steel. Following is a chart showing the comparisons between diamond and several minerals:

Diamond MOE (Modulus of Elasticity) is 900Gpa, which is much higher than that of hard alloy and almost all the other minerals in natural world. MOE means the material hardness and the formation during processing procedure. The higher the MOE, the less a material becomes deformation. Therefore, diamond used as abrasives can reduce workpiece internal stress so as to avoid cracks or other flaws.

Diamond is easy to fracture when confronted with impact force. Diamond impact resistance ability has something to do with crystal form, flaw and size. Therefore, special attention should be paid when producing and using diamond tools. The following chart displays some figures concerning diamond and some abrasive grains in aspects of MOE, bending strength, compressive strength: