Microstructure's Impact on Tool Wear During Drilling of Wrought and WAAM Fabricated Ti6Al4V Alloy
Authors :- J Singla, N Kumar, A Bansal, AK Singla, N Khanna
Publication :- ASME Mechanical Engineering Congress and Exposition – India, 2025
Ti6Al4V alloy’s strong strength, low density, and higher corrosion resistance makes it promising for use in a variety of components for automobile and aerospace industries. Wire Arc Additive Manufacturing-Cold Metal Transfer (WAAM-CMT), a contemporary direct energy deposition technology beneath the of additive manufacturing techniques, can be utilized for fabrication of big and complicated parts owing to its properties like high deposition rate, less heat supplied heat input, small spatter, enhanced dimensional performance, and large energy efficiency. Therefore, in this research work, Ti6Al4V alloy was fabricated using WAAM-CMT technique in argon designed chamber in order to avoid oxidation. under designed chamber. Additionally, Additive manufacturing parts typically require postprocessing mainly machining to remove surface flaws, making them suitable for industrial application. Therefore, to compare the machinability of conventional and WAAMed Ti6Al4V alloy components, TiN-coated carbide spiral drill bit has been used for drilling under LCO2 environment. Additive manufactured alloy exhibited a distinct microstructure of needle type structure with higher percentage of β grains as compared to conventional one, that showed equiaxial grains with higher percentage of α grains. Tool wear was observed to be greater for drilling of WAAMed Ti6Al4V alloy due to its high hardness and ultimate strength owing to fine structure of α phase in comparison to as-cast material. Tool degradation mechanisms in WAAMed Ti6Al4V alloy were found to have higher adhesion and edge chipping which may be due to higher hardness and enhanced sticking tendency of α and β grains. However, built up edge (BUE) in this case is smaller than that may have been resulted from presence of more β grains. Alternatively, larger BUE and smaller edge chipping were formed during drilling of wrought Ti6Al4V alloy that directly links to the presence of equiaxed grains and less percentage of β grains, respectively.