Tensile Properties of Vacuum Heat-treated Ti6Al4V Alloy Processed by Selective Laser Melting

Abstract

This study presents an investigation on the tensile behaviour of heat-treated titanium alloy (Ti6Al4V) parts, which have been manufactured by Selective Laser Melting (SLM) additive manufacturing. The parts were heat treated at a temperature of 850°C for 2 hours with and without Argon inert gas in a vacuum furnace. The tensile properties of the SLM samples with and without heat treatment have been compared to evaluate the mechanical performance of the 3D printed samples. The ultimate tensile strength (UTS) of as built Ti6Al4V part was found to be 1175 MPa. The UTS of heat-treated Ti6Al4V sample in vacuum without Argon gas was found to be 750MPa, while the UTS of heat-treated sample in vacuum with Argon gas was recorded as 980MPa. These values compare well with other published values of UTS for SLM built Ti6Al4V alloys with similar heat-treated conditions. The work also studied the micro-hardness of all the samples and compared the values with each other and found that the heat treated sample have lower average Vickers hardness values compared to as built samples.