Pulsed Plasma Surfacing of Titanium Matrix Cermet Based on B4C

Pulsed plasma transferred arc surfacing is presently used in many industrial applications to make protective layers against corrosion, temperature exposition, and excessive wear. Increasing wear resistance is especially important in areas of industry where titanium alloys are used, such as aviation and cosmonautics, because the wear resistance of titanium alloys is often weak. One way to increase the wear resistance is to deposit or form a cermet with a titanium matrix (TMC) on the surface of the part. The present study deals with the fabrication and characterization of TMC based on B 4 C. TMC with B 4 C was formed by co-feeding Ti6Al4V and B 4 C powder into a melting pool. Two B 4 C powders with different grain size were mixed with Ti6Al4V matrix in two ratios. It has been found that the deposited, thick layers have dispersed B 4 C grains in the matrix. The B 4 C grains partially dissolve in the titanium matrix to form borides and carbides. The resulting structure of the deposits is formed by a matrix with dispersed TiC x and TiB w particles; in some clusters, a full transformation of Ti was observed, resulting in regions containing only borides and carbides. The deposits are metallurgically connected to the substrate—Ti6Al4V. The TMCs were investigated in terms of microstructure and chemical composition and phase composition. Indentation hardness and reduced elastic modulus of individual phases were assessed by nanoindentation modulus mapping. Friction coefficient was determined using the linear pin test.