白铜/钢双金属管的瞬间液相扩散连接

Transient liquid phase diffusion bonding of Cu-Ni alloy/mild steel composite pipe

用扫描电镜组织观察、能谱微区成分分析、显微硬度、剪切试验、反复弯曲试验等方法，研究了以H62黄铜为中间层的B10白铜／20钢双金属管的瞬间液相扩散连接。结果表明，在950—1000℃扩散退火0．5～2h，白铜与低碳钢可以获得良好的冶金结合；黄铜与白铜间成分连续过渡，形成跨越界面的晶粒组织；在钢，黄铜界面，温度较低、时间较短时，形成珠光体富集带；高温长时间扩散，Cu，Ni，Zn向Fe中扩散形成硬度较高的组织．使界面塑性下降。

Composition,microstructure and performance of the TLP diffusion bonding zone of B10 Cu-Ni alloy/low carbon steel using H62 brass interlayer were examined by means of SEM and OM,EDX analysis,microhardness test, shear test and alternating bend test.Sound bonding was obtained between the two dissimilar materials at 950-1 000℃ for 0.5-2 h.At the brass/cupro-nickel interface,and composition changed gradually,and grains grew continuously,and no remarkable hardness change was detected.On the other hand,significant variation of composition was observed at the steel/brass interface.Pearlite-rich band was found parallel to the bonding line in the region of steel adjacent to the interface.As the time and/or temperature increased,iron-rich microstructure with higher hardness,resulting in a decrease of plasticity of the interface,was observed,.