Adequate Specimen Cooling
It has already been known that frictional heat formed by the rapidly rotating abrasive wheel helps break down the wheel bond and promote free cutting. This same heat if allowed to build up within the specimen could significantly alter the structure. In steels, incorrect cutting due to insufficient cooling and incorrect method could possibly result in the blue burn or even heat checking of the cut surface. These cutting flaws must be removed shortly by grinding to allow the true structure to be discovered; you can see this by using Metallographic microscopes. Abrasive wheels of different composition will change in their capacity to lessen burn. Correct wheel choice may be very critical in some applications, such as heat treated steels.
Enough specimens cooling require the example to be subjected to a constant flow of coolant. Even though water is an appropriate coolant, the addition of coolant additive to provide some lubrication and inhibit rust is what experts advise, to check if some steel has rust, you can view the surface using metallographic microscope. Submerge cooling is available on some cutters and provides the greatest cooling for cutting sensitive treated specimens. The coolant also used as a flush away to the waste products of cutting and to lessen the harmful odors which are very common in abrasive cutting with rubber wheel bonds.
Even though the function of the coolant is for specimen cooling, it also links the wheel and has an important control on the way it wears. Some effects of wheel profile on burr and cutting accuracy can be viewed with the use of Metallographic microscope. Aside from the fact that specimen cooling has an adequate flow rate but it should also be uniform. Regular cooling promotes a rather flat wheel profile or the even more desirable concave profile which produces a smallest amount of burring. A rounded wheel profile shows the wheel is too hard, a condition on which produces heavy burrs.
Non-uniform cooling causes the abrasive wheel to wear in an uneven manner. When cutting heavier sections, this could lead to curved cuts resulting in wheel seizure, stalling and finally, broken wheels and these thin sections are viewed by some metal experts using their most prized metallographic microscopes.
Specimen cooling therefore should be characterized by sufficient flow to avoid burning and regular flow to support even wheel-wear.