Mechanical performance of in-situ TiC-TiB2 composite coating deposited on Ti-6Al-4V alloy by powder suspension electro-discharge coating process

Abstract

Hard and wear resistance TiC-TiB2 coating was deposited on Ti-6Al-4V alloy by electro-discharge coating process using Ti and B4C powder suspended kerosene dielectric. Formation of TiC and TiB2 in combination with some intermediate phase via in-situ reaction of Ti and B4C due to spark energy has been confirmed through the XRD analysis of the coating. The microstructure analysis executed through SEM and corresponding EDS revealed that the peak current and duty factor has significant effect on the morphology of the coating. The microhardness measured at the top surface as well as at the cross-section of the coating show upto three times improvement in the hardness value compared to the Ti-6Al-4V substrate. The sliding wear test of the coating carried out against WC-Co ball revealed that the wear resistance of the coating improved upto seven times than the uncoated Ti-6Al-4V substrate.