Effects of laser processing on the transformation characteristics of NiTi: A contribute to additive manufacturing
Effects of laser processing on the transformation characteristics of NiTi: A contribute to additive manufacturing
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DOI：
10.1016/j.scriptamat.2018.04.024
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发表时间：
2018-07
影响因子：
6
通讯作者：
J. Oliveira;A. Cavaleiro;N. Schell;A. Stark;R. Miranda;J. Ocaña;F. B. Fernandes
中科院分区：
文献类型：
--
作者：
J. Oliveira;A. Cavaleiro;N. Schell;A. Stark;R. Miranda;J. Ocaña;F. B. Fernandes
NiTi 激光增材制造会产生复杂的微观结构特征，但尚未完全了解。激光微连接和激光增材制造之间的热相似性使得能够将两种工艺中激光对材料的影响关联起来。为了阐明它们，采用了一种简化但准确的方法：使用原位 X 射线衍射来确定激光加工的镍钛薄片中沿热影响区域的局部转变温度。观察到的转变温度梯度与镍损耗和残余应力引起的局部化学成分变化有关，解释了在镍钛增材制造中观察到的特殊微观结构和机械特征。
Laser additive manufacturing of NiTi generates complex microstructural features not fully understood yet. Thermal similarities between laser microjoining and laser additive manufacturing, enables correlating the effect of the laser on the material in both processes. To clarify them, a simplified yet accurate approach was employed: in-situ X-ray diffraction was used to determine the local transformation temperatures along the thermally affected regions in a laser processed NiTi thin sheet. The observed gradient of transformation temperatures is related to local chemical compositional changes through Ni depletion and residual stresses, explaining the peculiar microstructural and mechanical features observed in additive manufacturing of NiTi.