Ti-Zr-Cu-Ni-Co-Mo钎料的特性及其钎焊γ-TiAl接头的研究

Research on the characterization of Ti-Zr-Cu-Ni-Co-Mo filler and the brazed γ-TiAl joint

摘要:

采用SEM、EDS、XRD、TEM、DSC等对晶态和快速凝固Ti-25.65Zr-13.3Cu-12.35Ni-3Co-2Mo钎料的显微组织、熔化特性及相应钎焊γ-TiAl接头的界面显微组织进行了分析，并检测了钎焊接头的抗拉强度。结果表明：快速凝固Ti-Zr-Cu-Ni-Co-Mo钎料呈非晶态，其熔化区间比相应晶态的明显窄，且在γ-TiAl表面具有良好的润湿铺展性能。晶态和非晶态两种钎料的钎焊接头均包含界面反应层Ⅰ和中心钎焊层Ⅱ；当钎焊时间为10min、钎焊温度为925℃~1050℃时，随钎焊温度的升高，两种钎料的接头的抗拉强度均先增大后减小，且非晶钎料钎焊接头具有更高的抗拉强度。采用非晶钎料经1000℃钎焊10min获得的接头的抗拉强度最大，为302MPa。

Abstract:

The microstructure and melting characteristic of the Ti-25.65Zr-13.3Cu-12.35Ni-3Co-2Mo fillers prepared via casting and rapid solidification technology, as well as the interfacial microstructure of the brazed γ-TiAl joint were analyzed by SEM, EDS, XRD, TEM and DSC. The tensile strength of the brazed joint was also evaluated. The results show that the Ti-25.65Zr-13.3Cu-12.35Ni-3Co-2Mo filler prepared by rapid solidification is fully amorphous. The amorphous filler shows thinner melting temperature interval and better wettability to γ-TiAl compared with the crystalline filler. The joints brazed with crystalline and amorphous fillers are both composed of a central brazed layer II between two interfacial reaction layers I, and the tensile strength first increases and then decreases in the brazing temperature range of 925 - 1050 °C for 10 min. However, the tensile strength of the joints brazed with the amorphous filler is always much higher than that with the crystalline filler, and it obtains a maximum value of 302 MPa at temperature of 1000 °C with a holding time of 10 min.