Mechanical alloying behavior of Nb–Ti–Si-based alloy made from elemental powders by ball milling process
Mechanical alloying behavior of Nb–Ti–Si-based alloy made from elemental powders by ball milling process
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DOI：
10.1007/s12598-017-0881-1
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发表时间：
2017-02
期刊：
影响因子：
8.8
通讯作者：
Lijuan Zhang;Xiping Guo
中科院分区：
文献类型：
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作者：
Lijuan Zhang;Xiping Guo
采用机械合金化法制备了Nb-Ti-Si基合金粉末。从形貌、尺寸、相组成、晶粒尺寸、晶格应变、成分和内部微观结构等方面，采用X射线衍射（XRD）、扫描电子显微镜（SEM）、能谱仪（EDS）、激光粒度分析仪和透射电子显微镜（TEM）等分析手段对合金粉末进行了分析。随着球磨时间的增加，合金颗粒逐渐细化，形状逐渐趋于球形。球磨2 ~ 5 h时，Nb固溶体（Nb_2O_3）衍射峰向低2θ角方向移动，球磨5 ~ 70 h后，Nb_2O_3衍射峰向高2θ角方向移动，这主要是由于合金元素原子固溶到Nb晶格中形成Nb_2O_3，改变了Nb_2O_3粉末的晶格常数。球磨过程中，微晶尺寸减小，晶格应变增大，导致衍射峰不断展宽。球磨5 h后，粉末颗粒内部形成典型的片层组织，随着球磨时间的延长，片层组织变得更加细化和均匀。球磨40 h后，典型的层状组织消失，而是形成非常均匀的组织。这种均匀的显微组织被证明是由过饱和的铌酸盐相组成的。
Nb–Ti–Si-based alloy powders were prepared by mechanical alloying (MA) of elemental particles. The evolutions of morphology, size, phase constituents, crystallite size, lattice strain, composition and internal microstructure, etc., of the alloy powders were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), laser particle size analyzer and transmission electron microscope (TEM) analyses. The alloy particles are gradually refined and their shapes become globular with the increase in milling time. The diffraction peaks of Nb solid solution (Nbss) phase shift toward lower 2θangles during ball milling from 2 to 5 h, and after that Nbss diffraction peaks shift toward higher 2θangles with the increase in milling time from 5 to 70 h, which is mainly attributed to the alteration of the lattice parameter of Nbss powders due to the solution of the alloying element atoms into Nb lattice to form Nbss. During ball milling process, the decrease in crystallite size and increase in lattice strain of Nbss powders lead to continuous broadening of their diffraction peaks. A typical lamellar microstructure is formed inside the powder particles after ball milling for 5 h and becomes more refined and homogenized with the increase in milling time. After 40-h-ball milling, the typical lamellar microstructure disappears and a very homogeneous microstructure is formed instead. This homogeneous microstructure is proved to be composed of only supersaturated Nbss phase.