Dilution of Al and V through laser powder deposition enables a continuously compositionally Ti/Ti6Al4V graded structure

Abstract

Compositionally or functionally graded material are such a type of materials which can save material cost and weight, in the meantime directly meet the end user's specific need. In this work, a continuously compositionally graded Ti/Ti6Al4V material has been successfully synthesized by laser powder deposition (LPD). The compositionally graded Ti/Ti6Al4V profile is confirmed by electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and micro-area X-ray diffraction analysis (XRD), that V and Al contents continuously transit from Ti to Ti6Al4V. The graded material is free of cracks and intermetallics. The hardness and elastic modulus, obtained from nanoindentation tests, gradually increase from the Ti substrate to Ti6Al4V, displaying promising potential in application such as automotive and aerospace. Moreover, we discuss in details the effect of the dilution of Al and V on the formation a completely solid solution Ti-Al-V phase, and on the mechanical properties of the graded materials. Our findings not only shed lights on the application of LPD on compositionally or functionally graded materials, but also help researchers to control the phase composition through dilution from LPD.