The microstructures and properties of the Zn-Cu-Bi-Sn(ZCBS) high-temperature solders with various Sn contents were studied using differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and X-ray diffr...The microstructures and properties of the Zn-Cu-Bi-Sn(ZCBS) high-temperature solders with various Sn contents were studied using differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and X-ray diffraction(XRD).The results indicate that the increase of Sn content can both decrease the melting temperature and melting range of ZCBS solders and it can also effectively improve the wettability on Cu substrate.The shear strength of solder joints reaches a maximum value with the Sn addition of 5%(mass fraction),which is attributed to the formation of refined β-Sn and primary ε-CuZn_5 phases in η-Zn matrix.However,when the content of Sn exceeds 5%,the shear strength decreases due to the formation of coarse β-Sn phase,which is net-shaped presented at the grain boundary.展开更多
Cu75Pt25 brazing filler was applied to brazing GH99 superalloy to Nb,and the sound joints were obtained by adjusting brazing parameters.The typical interfacial microstructure of the brazed joint was Nb/Nb7Ni6+NbNi3/Ni...Cu75Pt25 brazing filler was applied to brazing GH99 superalloy to Nb,and the sound joints were obtained by adjusting brazing parameters.The typical interfacial microstructure of the brazed joint was Nb/Nb7Ni6+NbNi3/Ni(s,s)+Cr-rich NbNi3+(NbCr2+NbNi3)/GH99.The effects of brazing temperature and holding time on the interfacial microstructure of GH99/Cu75Pt25/Nb joints were studied.The results showed that the solution and diffusion of Ni atoms from GH99 substrate into brazing seam played a critical role in the interfacial microstructure evolution.As the brazing temperature rose,the Nb−Ni reaction layer was formed instead of the initial Nb3Pt layer,and the thickness increased firstly and then remained constant.The highest shear strength of the joint reached 152 MPa when brazed at 1150℃ for 15 min.All of the joints presented a brittle fracture mode during shear test,and the fracture location changed from Nb3Pt layer to Nb−Ni compounds layer.展开更多
The influence of brazing temperature and brazing time on the microstructure and shear strength ofγ-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler was investigated using SEM,EDS,XRD and universal testing ma...The influence of brazing temperature and brazing time on the microstructure and shear strength ofγ-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler was investigated using SEM,EDS,XRD and universal testing machine.Results show that all the brazed joints mainly consist of four reaction layers regardless of the brazing temperature and brazing time.The thickness of the brazed seam and the average shear strength of the joint increase firstly and then decrease with brazing temperature in the range of 1090-1170℃and brazing time varying from 0 to 20 min.The maximum shear strength of 262 MPa is obtained at 1150℃for 10 min.The brittle Al3NiTi2 and TiNi3 intermetallics are the main controlling factors for the crack generation and deterioration of joint strength.The fracture surface is characterized as typical cleavage fracture and it mainly consists of massive brittle Al3NiTi2 intermetallics.展开更多
Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron micros...Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. The strength and resistance of the joints were tested. It is found that when the brazing parameters are optimized, the structures of the joints are graphite/（Cu,Ni）/Ni（s.s）＋NixPy/Cu3P＋Cu（s.s） （including Sn）＋eutectic structures （Cu3P＋Ni3P＋Cu（s.s）/Cu （s.s）/Cu）. When the temperature increases to 750℃ or the holding time prolongs to 300 s, the eutectie structures disappear and the amount of Cu3P increases. The maximum shear strength of the joints is 5.2 MPa, which fracture at the interface of graphite and metallization. The resistance of the joints is no more than 5 mΩ.展开更多
基金Project(20115003)supported by the Program for the Development of Science and Technology of Jilin Province,China
文摘The microstructures and properties of the Zn-Cu-Bi-Sn(ZCBS) high-temperature solders with various Sn contents were studied using differential scanning calorimetry(DSC),scanning electron microscopy(SEM) and X-ray diffraction(XRD).The results indicate that the increase of Sn content can both decrease the melting temperature and melting range of ZCBS solders and it can also effectively improve the wettability on Cu substrate.The shear strength of solder joints reaches a maximum value with the Sn addition of 5%(mass fraction),which is attributed to the formation of refined β-Sn and primary ε-CuZn_5 phases in η-Zn matrix.However,when the content of Sn exceeds 5%,the shear strength decreases due to the formation of coarse β-Sn phase,which is net-shaped presented at the grain boundary.
基金Projects(51905125,51775138,U1737205)supported by the National Natural Science Foundation of ChinaProject(ZR2019BEE031)supported by the Natural Science Foundation of Shandong Province,ChinaProjects(2017GGX40103,2019GHY112069)supported by the Key Research and Development Program of Shandong Province,China。
文摘Cu75Pt25 brazing filler was applied to brazing GH99 superalloy to Nb,and the sound joints were obtained by adjusting brazing parameters.The typical interfacial microstructure of the brazed joint was Nb/Nb7Ni6+NbNi3/Ni(s,s)+Cr-rich NbNi3+(NbCr2+NbNi3)/GH99.The effects of brazing temperature and holding time on the interfacial microstructure of GH99/Cu75Pt25/Nb joints were studied.The results showed that the solution and diffusion of Ni atoms from GH99 substrate into brazing seam played a critical role in the interfacial microstructure evolution.As the brazing temperature rose,the Nb−Ni reaction layer was formed instead of the initial Nb3Pt layer,and the thickness increased firstly and then remained constant.The highest shear strength of the joint reached 152 MPa when brazed at 1150℃ for 15 min.All of the joints presented a brittle fracture mode during shear test,and the fracture location changed from Nb3Pt layer to Nb−Ni compounds layer.
基金Project(51865012)supported by the National Natural Science Foundation of ChinaProject(20202BABL204040)supported by the Natural Science Foundation of Jiangxi Province,China+3 种基金Project(2016005)supported by the Open Foundation of National Engineering Research Center of Near-net-shape Forming for Metallic Materials,ChinaProject(GJJ170372)supported by the Science Foundation of Educational Department of Jiangxi Province,ChinaProject(JCKY2016603C003)supported by the GF Basic Research Project,ChinaProject(JPPT125GH038)supported by the Research Project of Special Furnishment and Part,China。
文摘The influence of brazing temperature and brazing time on the microstructure and shear strength ofγ-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler was investigated using SEM,EDS,XRD and universal testing machine.Results show that all the brazed joints mainly consist of four reaction layers regardless of the brazing temperature and brazing time.The thickness of the brazed seam and the average shear strength of the joint increase firstly and then decrease with brazing temperature in the range of 1090-1170℃and brazing time varying from 0 to 20 min.The maximum shear strength of 262 MPa is obtained at 1150℃for 10 min.The brittle Al3NiTi2 and TiNi3 intermetallics are the main controlling factors for the crack generation and deterioration of joint strength.The fracture surface is characterized as typical cleavage fracture and it mainly consists of massive brittle Al3NiTi2 intermetallics.
基金Project(50705022) supported by the National Natural Science Foundation of ChinaProject supported by the Program for New Century Excellent Talents in University
文摘Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. The strength and resistance of the joints were tested. It is found that when the brazing parameters are optimized, the structures of the joints are graphite/（Cu,Ni）/Ni（s.s）＋NixPy/Cu3P＋Cu（s.s） （including Sn）＋eutectic structures （Cu3P＋Ni3P＋Cu（s.s）/Cu （s.s）/Cu）. When the temperature increases to 750℃ or the holding time prolongs to 300 s, the eutectie structures disappear and the amount of Cu3P increases. The maximum shear strength of the joints is 5.2 MPa, which fracture at the interface of graphite and metallization. The resistance of the joints is no more than 5 mΩ.
