Additive manufacturing of a functionally graded material from Ti-6Al-4V to Invar: Experimental characterization and thermodynamic calculations
Additive manufacturing of a functionally graded material from Ti-6Al-4V to Invar: Experimental characterization and thermodynamic calculations
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DOI：
10.1016/j.actamat.2016.12.070
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发表时间：
2017-04-01
期刊：
影响因子：
9.4
通讯作者：
Beese, Allison M.
中科院分区：
文献类型：
--
作者：
Bobbio, Lourdes D.;Otis, Richard A.;Beese, Allison M.
在功能梯度材料（FGM）中，组件内的元素组成或结构作为位置的函数逐渐变化，允许从一种合金逐渐过渡到另一种合金，以及局部定制性能。一种用于制造具有不同元素组成的FGM的方法是通过逐层定向能量沉积增材制造。这项工作结合了实验表征和计算分析，以研究从Ti-6Al-4V到Invar 36（64 wt% Fe，36 wt% Ni）的材料。的显微组织，成分，相，和显微硬度被确定为功能梯度材料内的位置的函数。在制造过程中，与Ti-6Al-4V和因瓦合金的成分混合相关的有害相形成，导致最终沉积部件开裂。金属间相（FeTi，Fe 2 Ti，Ni 3 Ti和NiTi 2）被实验确定为发生在整个梯度区域，并被认为是FGM在制造过程中开裂的原因。同时使用CALPHAD（相图计算）热力学计算来预测制造过程中将形成的相，并与实验结果进行比较。本文描述的用于表征FGM的实验-计算方法可以用于改善对其他FGM的理解和设计。(C)2016 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
In functionally graded materials (FGMs), the elemental composition, or structure, within a component varies gradually as a function of position, allowing for the gradual transition from one alloy to another, and the local tailoring of properties. One method for fabricating FGMs with varying elemental composition is through layer-by-layer directed energy deposition additive manufacturing. This work combines experimental characterization and computational analysis to investigate a material graded from Ti-6Al-4V to Invar 36 (64 wt% Fe, 36 wt% Ni). The microstructure, composition, phases, and microhardness were determined as a function of position within the FGM. During the fabrication process, detrimental phases associated with the compositional blending of the Ti-6Al-4V and Invar formed, leading to cracking in the final deposited part. Intermetallic phases (FeTi, Fe2Ti, Ni3Ti, and NiTi2) were experimentally identified to occur throughout the gradient region, and were considered as the reason that the FGM cracked during fabrication. CALPHAD (CALculation of PHase Diagrams) thermodynamic calculations were used concurrently to predict phases that would form during the manufacturing process and were compared to the experimental results. The experimental-computational approach described herein for characterizing FGMs can be used to improve the understanding and design of other FGMs. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.