The influence of cooling rate on the microstructure and phase fraction of gas atomized NiAl3 alloy powders during rapid solidification
The influence of cooling rate on the microstructure and phase fraction of gas atomized NiAl3 alloy powders during rapid solidification
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DOI：
10.1016/j.vacuum.2018.08.057
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发表时间：
2018-11-01
期刊：
影响因子：
4
通讯作者：
Liu, Xinyu
中科院分区：
文献类型：
--
作者：
Sang, Liming;Xu, Yi;Liu, Xinyu
采用氮气雾化法制备NiAl 3合金粉末。采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）和电子背散射衍射仪（EBSD）对不同粒度的粉体进行了显微结构和相组成的表征。雾化粉末由Ni2Al3，NiAl3和Al共晶相组成，并确定了三种主要类型的凝固组织：枝晶，细化枝晶和化合物。测量了直径为60、140和220 μ m的三种代表性颗粒的相分数。采用牛顿传热模型和经典非均质成核模型，分析了传热系数和冷却速率对液滴热历史的影响。实验结果与理论计算吻合较好，对进一步制备高NiAl 3相Raney镍催化剂粉末具有指导意义。
NiAl3 alloy powders were produced by nitrogen gas atomization in this paper. The microstructure and phase compositions of different particle size powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electron backscattered diffraction (EBSD). The atomized powders are composed of Ni2Al3, NiAl3 and Al-eutectic phases, and three main types of solidification microstructures were identified: dendrites, refined dendrites, and compounds. Phase fraction of three representative particles with diameter of 60, 140 and 220 mu m were measured. Moreover, the Newtonian heat transfer formulation coupled with the classical heterogeneous nucleation was used for analyzing the influence of heat transfer coefficient and cooling rate on the thermal history of droplets. Therefore, this work highlights the experimental results matched well with the theoretical calculation and guides the further production of high NiAl3 phase Raney nickel catalytic powders.