Taşlama çarkı (P233-246-2)

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.

SDC: The metal-clad composed by thick nickel or copper layer. It can reach 60% of total weight of grain. These clad grains are often applied in resin-connected tools, like grinding wheel. The function of cladding is to improve the wear resistance of connecting part, and help emit the heat produced during grinding, so the property of tool is improved.

CBN is CNB abrasive material, mainly applied in grinding wheel and polishing tools, mechanically machining hard iron workpieces. These tools are extensively applied in automobile and astronautic industries, to produce high precision parts such as gear, bearing, cam shaft, crank shaft as well as engineering parts.

Diamond means the diamond abrasive materials applied in precision grinding wheel, polishing tools that mechanically machine non-ferrous materials. These tools are extensively applied in industry to mechanically machine materials including glass, carbonized tungsten and ceramics.

Cubic Boron Nitride (CBN) is the known second hardest material, second only to hardness of diamond. CBN is composed by h-BN, similar as combing graphite into diamond.

Expected characteristics of grinding agent include high hardness, wear-resistance, power and high temperature resistance and chemical corrosion resistance, keep sharp cutting side during using. Comparing with ordinary grinding agent like carbonized Silicon and aluminum oxide, CBN exceeds its value in most of key demand. Its high heat-resistance and chemical corrosion-resistance make it applied in machining ferrous material. Generally, diamond wear-resistant materials are not applied in ferrous environment.

Hardness is the most physical property of grinding materials. The majority of grinding materials will lose their hardness at high temperature. Comparing with ordinary grinding materials, one of CBN's physical strength lies in its hardness keeping at higher temperature range beside that it has better hardness at extreme high temperature.