| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Processing—Microstructure—Property Relationships of Titanium and Titanium Alloys
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| Presentation Title |
Exploiting Structural and Compositional Instabilities in Titanium Alloys to Optimize Microstructure/Property Interrelationships in Samples Fabricated by Additive Manufacuring |
| Author(s) |
Brian A. Welk, Nevin Taylor, Zachary T. Kloenne, Yufeng Zheng, Rajarshi Banerjee, Hamish L. Fraser |
| On-Site Speaker (Planned) |
Hamish L. Fraser |
| Abstract Scope |
Regarding additive manufacturing (AM) of titanium alloys there are two problems to be solved, the first involving the need to effect an equaixed microstructure in printed parts, rather than the coarse columnar microstructure that is usually observed, and the second is the optimization of microstructure by post-processing heat-treatments. Using the alloy Ti-6Al-4V, the first of these problems has been solved by use of dilute alloying, added to increase the freezing range and so the probability of solutal undercooling during the rapid solidification experienced in AM. Interestingly, the addition of 3%Fe to Ti-64 changes the nature of the alloy from an alpha/beta alloy to a metastable beta Ti alloy. This allows for heat-treatments that are different from those applied to Ti-64, and involve exploitation of structural and compositional instabilities to produce refined microstructures uisng heat-treatments that do not make use of rapid quenching from a temperature above the beta transus. Hence, these heat-treated samples exhibit refined microstructures and do not possess significant residual stresses. Preliminary assessments of mechanical properties will be presented. |