Optimizing Laser Parameters of Functional Graded Grade 5 Titanium Alloy (TI6AL4V) and Titanium Carbide (TIC)

Abstract

Functionally graded materials (FGMs) are materials in which the spatial chemical composition and microstructure gradually change resulting in a corresponding spatial change in the material properties. For this study, grade 5 titanium alloy (Ti6Al4V) and titanium carbide (TiC) powders were co-sintered using laser metal deposition (LMD) on Ti6Al4V substrate. The challenge of this process was determining the process parameters that minimizes or prevent macro cracking due to high thermal gradients and hence the residual stresses. The aim was to determine the optimum parameters. The laser energy density (LED) was used to characterize the processing parameters applied. It was found that when the energy density is in the range of 15 - 25 MJ/m2, the FGM cracked. When the energy density is in the range of 12 - 16 MJ/m2, the FGM did not crack.