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Processing of zirconium boride-zirconium carbide-zirconium disilicide ceramic by reactive metal penetration.

机译:通过活性金属渗透处理硼化锆-碳化锆-二硅化锆陶瓷。

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摘要

The processing of ZrB2-ZrC-ZrxSi y composite by reactive metal penetration was investigated as a successor to the ZrB2-SiC composites for hypersonic vehicles application, which cannot be used for extended time at temperatures greater than 1600°C due to formation of SiO and CO gases. Zirconium (Zr), zirconium disilicide (ZrSi2), and boron carbide (B4C) were reacted in graphite crucibles for 60, 120, 180, and 240 minutes. Microscopy and x-ray diffraction (XRD) deduced the formation of a heterogeneous microstructure of ZrB 2-ZrC-ZrxSiy precipitates surrounded by a solidified Zr-Si melt. Unreacted boron carbide was observed in samples held at 1860°C for 60 minutes and 120 minutes, so thermodynamic equilibrium was not achieved. The reaction for the composite formation is as follows: Zr+B4C+ZrSi2→ZrB2 +ZrC+ZrxSiy The most consistent microstructures were seen on the samples heated for 180 minutes and 240 minutes, in which the free B4C completely decomposed to zirconium boride and carbide. Also, because of the closeness of the initial compositions of Zr and Si (12 wt% and 14 wt%) on the Zr-Si phase diagram, there was not much difference in the final phases obtained in both compositions.
机译:研究了反应性金属渗透对ZrB2-ZrC-ZrxSi y复合材料的加工,该工艺是高超声速车辆应用ZrB2-SiC复合材料的后继产品,由于形成SiO和H,不能在超过1600°C的温度下长时间使用。一氧化碳气体。锆(Zr),二硅化锆(ZrSi2)和碳化硼(B4C)在石墨坩埚中反应60、120、180和240分钟。显微镜和X射线衍射(XRD)推断出ZrB 2-ZrC-ZrxSiy沉淀物被凝固的Zr-Si熔体包围的异质微观结构的形成。在1860°C下放置60分钟和120分钟的样品中观察到未反应的碳化硼,因此无法实现热力学平衡。复合物形成的反应如下:Zr + B4C + ZrSi2→ZrB2 + ZrC + ZrxSiy在加热180分钟和240分钟的样品上观察到最一致的微观结构,其中游离的B4C完全分解为硼化锆和碳化物。 。另外,由于在Zr-Si相图上Zr和Si的初始组成(12wt%和14wt%)的紧密性,在两种组成中获得的最终相没有太大的差异。

著录项

  • 作者

    Maheswaraiah, Nischel B.;

  • 作者单位

    The University of Texas at El Paso.;

  • 授予单位 The University of Texas at El Paso.;
  • 学科 Engineering Aerospace.;Engineering Materials Science.;Engineering Mechanical.
  • 学位 M.S.
  • 年度 2010
  • 页码 66 p.
  • 总页数 66
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 语言学;
  • 关键词

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