Effect of laser power and scanning speed on the characteristics of laser metal deposition of Ti6Al4V + W composite powder on Ti6Al4V substrate

Abstract

The usage of different powders to enhance the surface properties of base materials has an impact on the cost. Laser Metal Deposition (LMD) of Ti6Al4V + W composite was used and the effect of laser power and scanning speed was investigated. The microstructure, microhardness, and x-ray diffraction analyses, and wear tests were conducted. The microstructure of the samples fabricated using higher laser power (1400W) displayed larger grains when compared to the ones fabricated using lower laser power (800 W). The Full Width at Half Maximum (FWHM) values showed some changes with the variation of scanning speeds. Furthermore, the x-ray diffraction patterns did not show the formation of new phases. A similar trend on the microhardness profiles for all the fabricated samples was observed. Higher microhardness values were observed in the top part of the deposited material. The microhardness profile showed similar trends for all the analysed samples. Higher microhardness values were measured at the top of deposition and decreased progressively. On the other hand, the scanning speed did not affect the wear volume, though the highest wear volume of 0.144 mm was observed for the sample fabricated using 800 W laser power and 0.7 m min ^−1 . This shows that process parameters such as laser power and scanning have an impact on the resulting properties of deposited composite material.

Keywords

• laser metal deposition (LMD)
• Ti6Al4V
• tungsten
• microstructure
• microhardness
• wear