Characterisation of laser metal deposited titanium and molybdenum composite

Laser Metal Deposition (LMD) is a unique way of building components by adding the material(s) layer by layer until the components are built. This process is based on the geometry path defined by the CAD model data form the component development. This paper reports on the characterization of Laser Metal Deposited Titanium alloy and Molybdenum Powder on Titanium alloy grade 5 substrate. The depositions are the process of delivering of the Titanium and Molybdenum powder from a powder feeder of two different hoppers containing each powder. The deposited samples were achieved through the combination of different ratios of Titanium and Molybdenum, i.e. 95%, 90% and 85% of Titanium and 5%, 10%, 15% Mo respectively. Three sets of experiments were conducted with multiple tracks at a constant laser power of 1.2kW, Scan speed of 0.5m/min and gas flow rate at 2 l/min. While the powder flow rate for both Ti6Al4V and Mo were varied. The deposits were sectioned through the thickness, metallographically prepared and characterized through microstructural evaluation and microhardness. The results from the microstructure revealed that columnar grains describe the layers, which gives an excellent interfacial bonding between the layers. The Micro Vickers hardness values were observed to decrease as the percentage of Mo increases. Through the EDS, the un-melted powders and pores were identified. Also, the grain sizes were found to reduce as the percentage of Molybdenum increases.