Powder flow rate influence on laser metal deposited TiC on Ti-6A1-4V

Laser metal deposition (LMD) presents a suitable substitute for conventional machining of titanium products. It is an additive manufacturing technology used to build prototypes, models, tools, dies and end products. The process is used to manufacture components from materials, which are difficult to machine through conventional methods. Titanium and its alloys are one of the difficult materials to machine since they cause galling on the cutting tool. This paper reports on the material characterization of Laser Metal deposited TiC on Titanium alloy grade S and the effect of varying the powder flow rate on the evolving properties of the material. The clads were characterized through microstructural analysis, hardness and degree of porosity. The physical appearances of the samples appeared sound without defect. However, the surfaces of the samples were rough. Furthermore, the average microhardness decreased as the powder flow rate was increased. The microstructural evaluation revealed that the grain size in the deposit zone becomes shorter as the powder flow rate was increased. The microstructure in the heat-affected zone had smaller grain sizes relative to the grain sizes in the deposit zone. In addition, the porosity characterization revealed that the number of pores increases when the powder flow rate increases.