Mechanical Properties Including Fatigue of CP Ti and Ti-6Al-4V Alloys Fabricated by EBM Additive Manufacturing Method

摘要

The Electron Beam Melted (EBM) method is one of the attractive attention thing additive manufacturing methods. By using an EBM additive manufacturing method, CP Ti and Ti-6Al-4V specimen were fabricated with a certain processing parameters. The mechanical properties such as fatigue limit, tensile properties including microstructural characteristics of CP Ti and Ti-6Al-4V specimens fabricated by EBM were confirmed and were compared with the conventional Ti alloys. Additive manufacturing was obtained high strength by creating martensite due to rapid cooling. On the other hand, void occurrence cannot be avoided by the method of using powder, accordingly it had a low fatigue strength value. Therefore, this study focused on that the values of fatigue characteristics of the EBM specimens and conventional specimens were compared and analyzed. EBM CP Ti had good mechanical properties such as yield strength, ultimate tensile strength, elongation and fatigue limits, approximately as same as casting CP Ti. EBM Ti-6Al-4V showed good mechanical properties, but fatigue limits were lower than wrought Ti-6Al-4V. That resulted from the formation of several kinds of internal pores which caused to increase the crack initiation and propagation.