Additively Manufactured Ti-6Al4V before and after Hot Isostatic Pressing

Abstract

The crystalline structure and mechanical properties of titanium 6Al 4V produced via selective laser sintering were compared to literature examples and to wrought samples. In total, three sets of samples were analyzed: wrought, as printed selective laser sintering samples with no post processing, and selective laser sintering samples that were further processed via hot isostatic pressing for final consolidation. Samples were sectioned to fit on graphitic resin pucks and cut from the build plane in two orthogonal planes. Images were taken using a TESCAN MIRA3 scanning electron microscope with electron backscatter diffraction analysis and samples were etched for optical analysis. Hardness of the samples was measured using a Vickers hardness indenter. The overall chemical composition of the samples, both AM and wrought, were similar as confirmed using energy dispersive spectroscopy. Beta grains were observed in a columnar orientation along the build direction, however, the grain orientation did not appear to affect the hardness of the sample. A small amount of grain growth was observed in the post processed samples as compared to the as printed samples.