Chapter 4 - Diamond tool fabrication

Abstract

The diamond impregnated tool components are initially produced by the powder metallurgy (PM) route and then, in the final stage, they are attached to the tool support, which may require further processing. The matrix powder preparation consists of mixing the selected component powders so as to achieve the pre-determined chemical composition, particle shape, and size distribution considering the final product application. The mixing process has a great effect on the quality of the final product. The non-uniform distribution of both matrix powder particles and diamond crystals causes premature wear of the segment. Therefore, when each diamond crystal is separately coated with the matrix powder, the formation of diamond clusters in the segment is practically eliminated. Cold pressing is always applied as a pre-sintering operation and prior to hot pressing in the manufacture of saw segments having a layered structure. The end product of the PM processing cannot be directly applied as a tool and must be subjected to further finishing operations. These involve attaching the diamond-impregnated segments, or beads, onto a suitable steel carrier, which is also equipped to cope with the forces applied during use.