Microstructural Evolution and Mechanical Properties of Laser Processed Ti6Al4V Sheets

This paper reports on the evolved microstructure and the mechanical properties of laser beam formed Ti6Al4V sheets processed at different parameters. Effective control of the process parameters is essential in achieving the desired properties for tailored applications. In addition, it will be easier to control one or two process parameters in order to achieve the expected material property than multiple parameters. The samples were produced by varying the laser power and the number of scans. The results revealed that controlling only the laser power during the forming process, the physical, mechanical and the microstructural properties of the processed materials could be effectively monitored and controlled. The micrograph shows an alpha and beta basket weave microstructure. The dark beta phase is finely embedded in the alpha phase. It was observed that the alpha-beta basket weave microstructure is denser at lower laser power. This implies that as the laser power increases, the density of the acicular alpha phase decreases; this is often attributed to the increased cooling effect during the laser forming process. It was observed that the Vickers microhardness value of the laser formed Ti6Al4V sheets at a constant scan speed of 0.05 m/min, increases as the laser power increases from 1000W to 1200W due to laser-material interaction. Similarly, the calculated UTS for the laser beam formed Ti6Al4V sheets increased as the Vickers microhardness value increases.