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 B4C. TMC with B4C was formed by co-feeding Ti6Al4V and B4C powder into a melting pool. Two B4C powders with different grain size were mixed with Ti6Al4V matrix in two ratios. It has been found that the deposited, thick layers have dispersed B4C grains in the matrix. The B4C 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 TiCx and TiBw 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.

Automated summary

Pulsed plasma transferred arc surfacing is a commonly used industrial technology for producing protective layers with high resistance to corrosion, high temperature, and wear. This study focuses on the fabrication and characterization of a titanium matrix based on B4C for improving wear resistance. The findings reveal that the B4C grains in the thick deposited layers partially dissolve in the titanium matrix, forming borides and carbides.