Effect of powder density variation on premixed Ti-6Al-4V and Cu composites during laser metal deposition

Abstract

This paper reports the effect of powder density variation on the premixed Ti-6Al-4V/Cu and Ti-6A-4V/2Cu Composites. Two sets of experiment were conducted in this study. Five deposits each were made for the two premixed composites. Laser powers were varied between 600 W and 1700 W while a scanning speed of 0.3 m/min is kept constant throughout the experiment. Investigations were conducted on the microstructures and microhardness of the laser deposited premixed Ti-6A-4V/Cu and Ti-6A-4V/2Cu composites. It was found that the evolving microstructures of the composites were characterised with the formation of macroscopic banding and Widmanstatten; and disappears as it grows towards the fusion zone (FZ) and this could be attributed to the changes in the distribution of heat input. Sample A2 of premixed Ti-6A-4V/Cu composite gives the highest hardness of 393 ± 6.36VHNo.5 while sample B4 of premixed Ti-6A-4V/2Cu composites depicts the highest hardness value of 373 ±9.18VHNo.5.