Transient liquid phase(TLP)bonding is a promising process for the joining and repairing of nickel-base superalloys.One of the most important parameters in TLP bonding is the bonding time required for suf-ficient isoth...Transient liquid phase(TLP)bonding is a promising process for the joining and repairing of nickel-base superalloys.One of the most important parameters in TLP bonding is the bonding time required for suf-ficient isothermal solidification which prevents the formation of undesirable precipitated phases.In the present work,the effect of bonding time on the microstructure,type,and evolution of precipitates in the non-isothermal solidified zone(NSZ)and their effect on micro-mechanical properties were systemat-ically investigated using multi-scale tests in TLP bonded Mar-M247 superalloy joints with Ni-15.2Cr-3.74B interlayer at 1230℃.For a bonding time of 5 min,dual-phase M_(23)(C,B)_(6)-γ/γ’(where M is a mix-ture of Hf,Ta,Cr,and Ni)with eutectic configuration was formed in NSZ.With the increase in bonding time,the evolution of NSZ microstructure can be summed up as eutectic M_(23)(C,B)_(6)-γ/γ’,semi-striping dual-phase M_(23)(C,B)_(6)-γ/γ’,discontinuously striping M_(23)(C,B)_(6)-γ/γ’,followed by the disintegration of NSZ.As the NSZ counterpart,the isothermal solidified zone(ISZ)is mainly composed ofγ/γ’.Ac-companied by the dissolution of M_(23)(C,B)_(6) in the centerline,the proportion of the ISZ increases greatly until the joints are completely occupied by ISZ.Finally,a bamboo-like structure with domain size of-100μm was formed in the joint centerline,along withγ’reorganized themselves all into cubic shapes and distributed homogeneously.Mechanical property tests demonstrated that in comparison to samples with longer bonding time,the NSZ of the shortest bonding time(5 min)has the highest strength and a subsequent decrease in strength was observed with prolonging the bonding time and post-bond heat treatment.Furthermore,possible solidification/transformation path,segregation behavior,and formation mechanism of NSZ/ISZ evolution were discussed.展开更多
在氩气保护下,用FeN iS iB非晶箔T91钢管进行了瞬时液相扩散连接.通过正交实验,研究了工艺参数对接头组织和性能的影响,分析了TLP连接接头的显微组织、力学性能和元素分布,确定出了合适的连接工艺参数.结果表明,在合适的工艺参数下,接...在氩气保护下,用FeN iS iB非晶箔T91钢管进行了瞬时液相扩散连接.通过正交实验,研究了工艺参数对接头组织和性能的影响,分析了TLP连接接头的显微组织、力学性能和元素分布,确定出了合适的连接工艺参数.结果表明,在合适的工艺参数下,接头可以获得良好的组织和性能.T91钢TLP连接工艺为温度1250℃,等温凝固时间3 m in,压力6 MPa.展开更多
基金supported by the National Natural Science Foundation of China(No.52125101)the Basic and Applied Basic Research Major Program of Guangdong Province,China(Grant No.2021B0301030003)the Jihua Laboratory(Project No.X210141TL210).
文摘Transient liquid phase(TLP)bonding is a promising process for the joining and repairing of nickel-base superalloys.One of the most important parameters in TLP bonding is the bonding time required for suf-ficient isothermal solidification which prevents the formation of undesirable precipitated phases.In the present work,the effect of bonding time on the microstructure,type,and evolution of precipitates in the non-isothermal solidified zone(NSZ)and their effect on micro-mechanical properties were systemat-ically investigated using multi-scale tests in TLP bonded Mar-M247 superalloy joints with Ni-15.2Cr-3.74B interlayer at 1230℃.For a bonding time of 5 min,dual-phase M_(23)(C,B)_(6)-γ/γ’(where M is a mix-ture of Hf,Ta,Cr,and Ni)with eutectic configuration was formed in NSZ.With the increase in bonding time,the evolution of NSZ microstructure can be summed up as eutectic M_(23)(C,B)_(6)-γ/γ’,semi-striping dual-phase M_(23)(C,B)_(6)-γ/γ’,discontinuously striping M_(23)(C,B)_(6)-γ/γ’,followed by the disintegration of NSZ.As the NSZ counterpart,the isothermal solidified zone(ISZ)is mainly composed ofγ/γ’.Ac-companied by the dissolution of M_(23)(C,B)_(6) in the centerline,the proportion of the ISZ increases greatly until the joints are completely occupied by ISZ.Finally,a bamboo-like structure with domain size of-100μm was formed in the joint centerline,along withγ’reorganized themselves all into cubic shapes and distributed homogeneously.Mechanical property tests demonstrated that in comparison to samples with longer bonding time,the NSZ of the shortest bonding time(5 min)has the highest strength and a subsequent decrease in strength was observed with prolonging the bonding time and post-bond heat treatment.Furthermore,possible solidification/transformation path,segregation behavior,and formation mechanism of NSZ/ISZ evolution were discussed.
文摘在氩气保护下,用FeN iS iB非晶箔T91钢管进行了瞬时液相扩散连接.通过正交实验,研究了工艺参数对接头组织和性能的影响,分析了TLP连接接头的显微组织、力学性能和元素分布,确定出了合适的连接工艺参数.结果表明,在合适的工艺参数下,接头可以获得良好的组织和性能.T91钢TLP连接工艺为温度1250℃,等温凝固时间3 m in,压力6 MPa.
