AgAlTi-C钎焊C_f/SiC复合材料与TC4接头组织结构

Microstructures of Composite Brazing Joints of C_f/SiC Composites and TC4 Using AgAlTi-C Filler Materials

研究用Ag粉、Al粉、Ti粉、短炭纤维配制以Ag-6Al为主的混合粉末真空钎焊Cf/SiC陶瓷基复合材料和钛合金,采用X射线衍射、扫描电镜和能谱仪对接头组织结构进行分析。结果表明:在Ag-6Al中加入Ti可以提高钎料对复合材料的润湿性并抑制钎料中Al的氧化,加入短炭纤维可以缓解接头热应力。在不同工艺条件下,真空钎焊得到了完整的复合接头,钎焊过程中生成的钛铝化合物在接头中细小均匀分布,在短炭纤维周围原位合成了TiC。当在Ag-6Al中加入一定质量分数的Ti和短炭纤维,在910℃保温10min的最佳工艺条件下得到的接头最高剪切强度达到90.8MPa。

Cf/SiC composite and TC4 were successfully joined by the mixed powders of Ag,Al,Ti and short carbon fibers under vacuum condition.The microstructure of the joints was investigated by X-ray diffraction,scanning electron microscopy and energy dispersive spectrometry.The results show that the maximum shear strength is 90.8MPa and the optimal parameter is brazing at 910℃ within 10min.The addition of short carbon fibers contributes a lot to the shear strength by alleviating the thermal stress of the joints and to the in-situ formation of TiC around the short carbon fibers.Ti element can improve filler metal＇s wettability to Cf/SiC composite and restrain the oxidation of Al element.