|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Solidification Processing of Light Metals and Alloys: An MPMD Symposium in Honor of David StJohn
||Identifying and Understanding the Influence of Columnar Beta-phase Boundaries on the Tensile and Fatigue Properties of Additively Manufactured Ti-6Al-4V Alloy
||Ma Qian, Huiping Tang , Jian Wang
|On-Site Speaker (Planned)
Fine equiaxed grains are preferred to columnar grains for metallic materials that are not concerned with creep-resistant applications. Ti-6Al-4V (wt.%) is the workhorse alloy of the titanium industry, whose usage amounts to more than 50% of the titanium market. It is also the most extensively studied alloy for additive manufacturing (AM). Ti-6Al-4V manufactured by fusion-based AM processes solidifies as essentially continuous columnar beta-phase grains parallel to the build direction. These columnar grain boundaries are retained at room temperature and also after post-AM heat treatments as long as the isothermal holding temperature is below the beta transus. Should such columnar grain boundaries be removed from the microstructure of the additively manufactured Ti-6Al-4V by either solidification control or applying post-AM heat treatments in the beta-phase region? Through well-designed experiments and detailed assessments of the tensile and fatigue properties of the additively manufactured Ti-6Al-4V, the answer from this study is clearly “No Need”.