點擊此處 ,將本頁翻譯成中文
將本頁翻譯成中文
您現在的位置:首頁> 外文學位 >文獻詳情
【6h】

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

【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.

【作者】Maheswaraiah, Nischel B.;

【作者單位】The University of Texas at El Paso.;

【授予單位】The University of Texas at El Paso.;

【學科】Engineering, Aerospace.;Engineering, Materials Science.;Engineering, Mechanical.

【學位】M.S.

【年(卷),期】2010(),

【年度】2010

【頁碼】66 p.

【總頁數】66

【原文格式】PDF

【正文語種】eng

【中圖分類】H0;

【關鍵詞】;

聯系方式:18141920177 (微信同號)

客服郵箱:kefu@zhangqiaokeyan.com

京公網安備:11010802029741號 ICP備案號:京ICP備15016152號-6 六維聯合信息科技 (北京) 有限公司?版權所有
  • 客服微信

  • 服務號

亚洲校园自拍卡通图片区_超清av在线播放不卡无码_人与动人物特级Av片在线观看_国产被弄到高潮正在播放