A comparative study of mechanical properties and machinability of wrought and additive manufactured (selective laser melting) titanium alloy - Ti-6Al-4V

Purpose - The purpose of this paper is to study and compare the mechanical properties and machinability characteristics of additive manufactured titanium alloy Ti-6Al-4V with conventionally produced wrought titanium alloy, Ti-6Al-4V. The difference in mechanical properties such as yield strength, ultimate tensile strength, micro hardness, percentage of elongation and their effect on machinability characteristics like cutting forces and surface roughness are studied. It was found that higher strength and hardness of SLM Ti-6Al-4V compared to wrought Ti-6Al-4V owing to its peculiar acicular microstructure significantly affected the cutting forces and surface roughness. High cutting forces and low surface roughness were observed during machining of additive manufactured components compared to its wrought counterpart because of their difference in strength, hardness and ductility. Design/methodology/approach - Mechanical properties like yield strength, ultimate tensile strength, hardness and percentage of elongation and machinability characteristics like cutting forces and surface roughness were studied for both wrought and additive manufactured Ti-6Al-4V. Findings - Mechanical properties like yield strength, ultimate tensile strength and hardness were higher for additive manufactured components as compared to the wrought component. However additive manufactured components significantly lacked in ductility as compared to the wrought parts. Concerning machining, higher cutting forces and lower surface roughness were observed in additive manufactured Ti-6Al-4V compared to the wrought part as a result of differences in mechanical properties of these differently processed materials. Originality/value - This paper, for the first time, discusses the machining capabilities of additive manufactured Ti-6Al-4V.