High quality SD/SDC diamond CBN/CBNC grinding wheel
Diamond: One of the crystalline forms of carbon(as the figure).It is historically known as a gemstone, however, it is the physically
hardest substance known and is now widely used as an abrasive in high productivity tools in industry. Diamond also has other obvious
physical characteristics:
Characteristics of diamond:
Density [g/cm3] !!3.52
Compressive strength [GPa] !!8.68
Fracture toughness[MPam1/2] !!3.40
Knoop hardness [Gpa] !!57-104
Young's modulus [GPa] !!1141
Thermal expansion [10-6K-1] !!1.5-4.8
Thermal conductivity [Wm-1K-1] !!500-2000
Coefficient of wear !!2.14-5.49
Diamond is the hardest known material. Due to its high wear-resistance, it has become the most frequently used industrial wear-resistant
material. Cutting and grinding stones, glass and other hard materials is only part of its early application. Diamond has one limit in its
application, that is, it can react with iron at high temperature (lead to reversion of graphite and cause high wear speed). Comparing
with other general abrasives, like aluminum oxide and Si-C compound, it is not economical, it is of higher cost.
Diamond is made from carbon. High temperature/high pressure or high temperature low pressure settling (like CVD) is the ordinary
combination of diamond.
CBN will not have this kind of reaction. Although its hardness is only half that of diamond, it is harder than general abrasives, so it
is very suitable to be used in ferrous work-piece as a high property abrasives.
Concentration means the weight of grain carat in unit volume of connecting material. For instance, a defined concentration is 0.44 carat
grain per cubic centimeter in the connecting material.
Hardness of combination is not hardness of grinding wheel grain. Grinding wheel with high hardness has stronger wear-resistance, but
grinding wheel with low hardness has weak wear-resistance, so the grinding force is small.