Wear Studies on TiC Coated Cemented Titanium Carbide Tools

Extensive and rigorous wear tests involving the failure criterion were carried out initially on (i) TiC coated and (ii) uncoated cemented tungsten carbide, and (iii) cemented titanium carbide (also known as solid TiC). The studies revealed that solid TiC was the best tool for turning steel followed closely by TiN coated tungsten carbide. The TiC coating confers many advantages but has certain limitations like cracks in the coating due to differences in the coefficients of thermal expansion between WC and TiC. Solid TiC tools perform better than TiC coated tungsten carbide tools but have the disadvantages of the binder being prone to diffusion wear. By putting a TiC coating on solid TiC, the new tool performed much better largely as a result of the absence of cracks as well as the binder in the coating. The further advantage of small grains, a property typical of coatings, added to the superior performance of TiC coated solid TiC as compared to uncoated solid TiC.