| 摘要: |
| 采用电弧熔炼TiNiB合金作为高温钎料对TiAl合金进行钎焊,研究了接头界面组织的形成及其随钎焊温度变化的演化过程.电弧熔炼的TiNiB合金钎料主要由Ti-Ni与TiNi3共晶组织及弥散分布的块状TiB2组成,DTA测试曲线表明钎料的熔点为1 120℃.钎焊过程中,TiAl基体向液态钎料中的溶解量决定了钎焊接头界面组织的形成及其演化过程.随着活性元素Ti和Al向液态钎料溶解量的增加,靠近钎缝侧的TiAl基体发生固态相变转化为β层;钎缝组织演化为Ti-Al-Ni三元化合物,并伴有少量的β相;块状的TiB2在过量活性元素Ti存在的情况下逐渐转变为长条状的TiB相. |
| 关键词: 钛铝合金 TiNiB钎料 钎焊 界面组织 |
| DOI： |
| 分类号: |
| 基金项目:黑龙江杰出青年基金资助项目(2004793) |
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| Microstructure of TiAl joints brazed with TiNiB high-temperature filler metal |
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YANG Zhenwen, ZHANG Lixia, XUE Qing, HE Peng
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State Key Lab of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China
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| Abstract: |
| High-temperature filler metal of TiNiB prepared by arc melting was used as an active filler metal in vacuum brazing of TiAl alloy.The effect of brazing temperature on the microstructure evolution of the joints was studied in this paper.The TiNiB filler metal was mainly comprised of TiNi and TiNi3 eutectic microstructure,in which some TiB2 blocks appeared.The melting point of the filler metal was 1 120℃.The dissolution of TiAl substrate has a strong effect on interfacial structure.The TiAl alloy adjacent to brazed seam was transformed to β layer with the dissolution of TiAl substrate.The microstructure of the brazed seam was comprised of Ti-Al-Ni compounds and a little β phase.TiB2 was transformed to TiB due to the reaction with Ti. |
| Key words: TiAl alloy TiNiB filler brazing microstructure |
