Influence of process parameters on porosity behaviour of laser metal deposited titanium composites

Abstract: This research paper reports the effect of laser power on the degree of porosity of the deposited tracks and characterized the specific porous structure. The results revealed that as the laser power was increased, the degree of porosity was however reduced. Prior the characterization process, titanium alloy and boron carbide (Ti6Al4V-B4C) composites powder were deposited on Ti6Al4V substrate using laser metal deposition (LMD) process through the application of Ytterbium fibre laser system. The laser power was varied between 800 W and 2400 W at interval of 200 W while all other process parameters were kept constant. The maximum capacity of this laser system is 3.0 KW which provides beam size of 4 mm for the control characterization of the deposited samples. After the deposition process, the samples were sectioned for porosity analysis and microstructural studies. The sectioned samples were however mounted, ground and polished according to standard metallurgical preparation of titanium alloys. The polished samples were then etched using Kroll’s reagent. Porosity analysis was observed using the optical microscope equipped with Analysis Docu Image Processing Software (ADIPS) to establish the percentage porosity and the maximum pore sizes of the composites..