New Boron and Silicon Free Single Crystal-Diffusion Brazing Alloys
New Boron and Silicon Free Single Crystal-Diffusion Brazing Alloys
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新型无硼无硅单晶扩散钎焊合金
DOI：
10.7449/2008/superalloys_2008_211_220
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
R. Singer
中科院分区：
文献类型：
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作者：
M. Dinkel;P. Heinz;F. Pyczak;Andreas Volek;M. Ott;E. Affeldt;A. Voßberg;M. Göken;R. Singer
开发并测试了用于单晶部件修复工艺的新型扩散钎焊合金。在这些二元钎焊合金中，锗被用作熔点降低元素，锗含量在 20 至 23 wt.% 之间。微观结构分析表明，在使用这些钎焊合金延长钎焊周期后，形成了单晶接头。在钎焊区内，除了所需的 γ´ 沉淀物之外，没有检测到第二相。这一结果针对两种母材 PWA 1483 和 Rene N5（分别是第一代和第二代高温合金）显示。对固化机制和动力学进行了检查，发现由于本系统中的多组分扩散，与二元系统的瞬态液相键合理论有相当明显的偏差。机械测试在室温下通过纳米压痕进行，在高温下通过热拉伸测试进行。纳米压痕结果显示钎焊接头和母材之间的硬度和弹性模量存在微小差异。在 980 °C 的拉伸测试中，与母材相比，极限拉伸强度提高了 90% 以上。
New diffusion brazing alloys for single crystalline component repair processes were developed and tested. Germanium was used as the melting point depressing element in these binary brazing alloys with germanium contents between 20 to 23 wt.%. Microstructural analysis has shown that the formation of a single crystalline joint was achieved after extended brazing cycles with these brazing alloys. No secondary phases other than the desired γ´ precipitates were detected within the brazing zone. This result was shown for two parent materials, PWA 1483 and Rene N5, a first and a second generation superalloy, respectively. The solidification mechanisms and kinetics were examined and show rather distinct deviations from Transient Liquid Phase Bonding theory for binary systems due to the multicomponent diffusion in the present system. Mechanical testing was performed at room temperature via nanoindentation and at elevated temperatures by hot tensile tests. The nanoindentation results show minor differences in hardness and elastic modulus between brazing joints and parent material. Ultimate tensile strengths of more than 90 % compared to the parent material were obtained in tensile testing at 980 °C.