Microstructural characteristics and high temperature compressive properties at 1623 K of a directionally solidified Nb-silisides based in-situ composite
Microstructural characteristics and high temperature compressive properties at 1623 K of a directionally solidified Nb-silisides based in-situ composite
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DOI：
10.1016/j.jallcom.2008.03.036
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发表时间：
2009-02
影响因子：
6.2
通讯作者：
J. Guo;Tian Yuzhen;G. Cheng;Limei Zhou;L. He;H. Ye
中科院分区：
文献类型：
--
作者：
J. Guo;Tian Yuzhen;G. Cheng;Limei Zhou;L. He;H. Ye
采用光学浮区熔炼技术制备了定向凝固Nb-22Ti-16Si-7Cr-3Al-3Ta-2Hf-0.1Ho(at.%)合金。通过扫描电子显微镜、X射线衍射仪、高分辨电子显微镜和压缩试验研究了该合金的组织特征和1623K高温压缩性能。DS结构显示出明显的胞状结构和沿生长方向的(Nb，Ti)ss(110)和(Nb，Ti)5Si3(310)强烈取向。(Nb，Ti)5Si3和(Nb，Ti)ss或(Ti，Nb)5Si3和(Nb，Ti)ss之间没有明确的晶体取向关系。硅化物与(Nb，Ti)SS之间的界面是干净的，但不是笔直和尖锐的。在1623K下，DS合金的高温压缩性能优于普通铸造(CC)合金。
The directionally solidified (DS) Nb–22Ti–16Si–7Cr–3Al–3Ta–2Hf–0.1Ho (at.%) alloy was fabricated by using optical floating zone (OFZ) melting technique. Microstructural characteristics and high temperature compressive properties at 1623K of the alloy were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution electron microscopy (HREM) and compressive tests. The DS microstructure exhibits an obvious cell structure and strong orientations of (Nb, Ti)ss (110) and (Nb, Ti)5Si3(310) along the growth direction. No definite crystallographic orientation relationship either between (Nb, Ti)5Si3and (Nb, Ti)ss or (Ti, Nb)5Si3and (Nb, Ti)ss was found. The interfaces between silicides and (Nb, Ti)ss are clean, but not straight and sharp. The high temperature compressive behavior of the DS alloy is superior to that of the conventional cast (CC) alloy at 1623K.