Comparison of Different Diamond Coatings in Co-based Bond Matrix for Wire Saws

An investigation is reported of the effects of three different coatings onto diamonds in the composites for the beads of wire saws. The matrix of the composites contained 80% (w/w) cobalt. Ti, W, and W-Co were coated onto diamond surfaces respectively and then incorporated into the matrix. The mixed powders were hot-pressed to form the specimens for bending tests. Coupled with the results of bending tests and the strength of coated diamonds, the coatings of W were found to be best among the three coatings. Further experiments indicated that the thickness of W-coatings onto the diamonds should be controlled around 10jtm in order to obtain an excellent retention of diamonds.