Characterization of Laser Deposited Ti6Al4V/TiC Composite Powders on a Ti6Al4V Substrate
R.M. Mahamood, E.T. Akinlabi, M. Shukla and S. Pityana
This paper reports the material characterization of Ti6Al4V/TiC composite produced by laser metal deposition. The Ti6Al4V/TiC composites were deposited with a composition ratio of 50 wt.% Ti64l4V and 50 wt.% TiC. The depositions were achieved by delivering the two powders from a powder feeder consisting of two different hoppers and each hopper contains each of the powders. A total of eight experiments were performed, the scanning speed was kept constant at 0.005 m/s and the laser power varied between 0.4 and 3.2 kW. The gas flow rate and the powder flow rates were also kept at constant settings of 1.44 g/min and 1 l/min respectively for each hopper. The deposits were laterally sectioned, metallographically prepared and characterized through microstructural evaluation, microhardness and wear resistance performance. The effects of varying the laser power on the resulting properties of the composites were studied extensively. The microstructure consists of un-melted carbide (UMC) in the matrix of alpha and prior beta grain structure of Ti6Al4V, and in varying degrees in all the samples. The results showed that the microhardness and the wear resistance performance were dependent on the laser power.
Keywords: coefficient of friction, laser material deposition (LMD), laser metal deposition, material characterization, Nd:YAG laser, Ti6Al4V, Ti64/TiC composite, wear resistance