Differences in the response of additively manufactured titanium alloy to heat treatment-Comparison between SLM and EBM

Abstract

Additive manufacturing (AM) of metals is expanding and already starts to reach industrial scale. Among many different technologies of AM, powder-bed technologies are the most widespread as they provide the highest resolution and so the widest options in the production of complex parts. Selective laser melting (SLM) and electron beam melting (EBM) both belong to this technological group. In this paper, we describe the differences between these two technologies on the example of titanium alloy production. Due to different material states in the as-built condition, the material shows a different response to heat treatment. We depict the differences by microstructure observations and hardness measurementafter annealing the titanium alloy at temperatures of 100-1000 °C and subsequent water quenching. While the titanium alloy is stable when manufactured by EBM, it shows microstructural changes associated with changes in mechanical properties when manufactured by SLM.