Center for Agile and Adaptive Additive Manufacturing, University of North Texas, Denton, TX, 76207, USA.
Department of Materials Science and Engineering, University of North Texas, Denton, TX, 76207, USA.
Nat Commun. 2023 Jun 6;14(1):3288. doi: 10.1038/s41467-023-38885-9.
In recent research, additions of solute to Ti and some Ti-based alloys have been employed to produce equiaxed microstructures when processing these materials using additive manufacturing. The present study develops a computational scheme for guiding the selection of such alloying additions, and the minimum amounts required, to effect the columnar to equiaxed microstructural transition. We put forward two physical mechanisms that may produce this transition; the first and more commonly discussed is based on growth restriction factors, and the second on the increased freezing range effected by the alloying addition coupled with the imposed rapid cooling rates associated with AM techniques. We show in the research described here, involving a number of model binary as well as complex multi-component Ti alloys, and the use of two different AM approaches, that the latter mechanism is more reliable regarding prediction of the grain morphology resulting from given solute additions.
在最近的研究中，在使用增材制造加工这些材料时，向钛和一些钛基合金中添加溶质已被用于产生等轴微观结构。本研究开发了一种计算方案，用于指导选择这种合金添加剂以及实现柱状到等轴微观结构转变所需的最小添加量。我们提出了两种可能产生这种转变的物理机制；第一个也是更常讨论的机制是基于生长限制因素，第二个机制是合金添加物所产生的凝固范围的增加，以及与 AM 技术相关的强制快速冷却速率。我们在描述的研究中表明，涉及一些模型二元以及复杂的多元钛合金，以及使用两种不同的 AM 方法，对于预测给定溶质添加物所产生的晶粒形态，后一种机制更可靠。
