摘要
研究了采用镍基含硼中间层合金在 1 2 2 0℃保温不同时间连接 IC- 6合金时 ,接头 90 0℃拉伸性能的变化。结果表明接头拉伸强度并未随扩散时间延长而不断提高。从断口分析可知 ,焊缝组织中的晶界强度和近缝区硼化物的形态、分布及数量决定了接头的拉伸强度和塑性。焊缝中的晶界强度高 ,裂纹沿晶界扩展至不利取向 ,转而沿近缝区硼化物扩展 ,断口上沿晶断裂所占区域少 ,对应接头强度较高 ,且具有一定的塑性。若晶界强度低 ,断口上主要表现为沿晶断裂 ,接头强度较低 ,且塑性差。在外应力作用下 ,硼化物发生脆性解理或由于与基体结合力低而脱开 ,其周围的包膜可以缓解硼化物上的应力集中 ,使裂纹扩展需要的应变能增加。
WT5BZ]900℃ tensile property of IC 6 joint TLP bonded using Ni based filler metal was studied Results show that the joint strength does not always increase with increasing bonding time The joint strength and ductility ware decided by the strength of grain boundaries in the bonding seam ,as well as the apperance,amount and distribution of borides formed at the faying surface In addition, less fractured areas along grain boundaries correspond to higher joint tensile strength and ductility The borides would fracture owing to brittleness and low coherence with the substrate γ′ film enclosing the borides would decrease stress concentration to hamper propagation of the cracks
出处
《材料工程》
EI
CAS
CSCD
北大核心
2000年第6期42-44,共3页
Journal of Materials Engineering
基金
国防预研基金
