In an attempt to develop low-silver brazing filler metals used for hermetic sealing materials in the vacuum interrupter industry,the ternary Ag-50Cu-5Ga low-silver vacuum brazing filler metal was investigated.The melt...In an attempt to develop low-silver brazing filler metals used for hermetic sealing materials in the vacuum interrupter industry,the ternary Ag-50Cu-5Ga low-silver vacuum brazing filler metal was investigated.The melting temperature was measured by differential scanning calorimetry(DSC),and the brazability of Ag-50Cu-5Ga alloy on copper and metallized copper/kovar were ascertained at 850℃under 1×10-4 Pa in this article.The microstructures of the filler metal and the joints have been analyzed by using scanning electron microscopy(SEM),equipped with an energy dispersive spectroscopy.The results show that vacuum brazing was success to join with copper or metallized copper/kovar using Ag-50Cu-5Ga filler and reliable joints were obtained.There were Ag-rich phase,Cu-rich phase and a fine eutectic structure of Ag-based solid solution and Cu-based solid solution in the copper joints and the width of brazing seam is about 60μm.The joints of kovar alloy to copper after surface nickel plating was composed of AgCu eutectic phase,Ag,Cu,Cu2Ga and CuNi2 phase.The tensile strength was 167 MPa and 150 MPa,respectively.The tensile results of joints show that the joint strengths were equivalent to the traditional brazing filler metals.展开更多
The influence of Mn on wettability and microstructure of low-silver solders was investigated. Mn degrades the wettability of low-silver solders, while the wettability of the Mn doping solders does not change with Mn c...The influence of Mn on wettability and microstructure of low-silver solders was investigated. Mn degrades the wettability of low-silver solders, while the wettability of the Mn doping solders does not change with Mn content in a linear way. As a result of Mn doping, the cellular/dendritic β-Sn and the eutectic phase are refined. It indicates that Mn promotes the spontaneous and heterogeneous nucleation process of the solder alloys. The growth of intermetallic compound on the joint inter＇ace during soldering is also restrained. Aging experiment shows that Mn suppresses the growth of Cu3Sn and Cu6Sn5 layers at the joint interface.展开更多
基金the National Key R&D Program of China(Grant No.2017YFB0305702).
文摘In an attempt to develop low-silver brazing filler metals used for hermetic sealing materials in the vacuum interrupter industry,the ternary Ag-50Cu-5Ga low-silver vacuum brazing filler metal was investigated.The melting temperature was measured by differential scanning calorimetry(DSC),and the brazability of Ag-50Cu-5Ga alloy on copper and metallized copper/kovar were ascertained at 850℃under 1×10-4 Pa in this article.The microstructures of the filler metal and the joints have been analyzed by using scanning electron microscopy(SEM),equipped with an energy dispersive spectroscopy.The results show that vacuum brazing was success to join with copper or metallized copper/kovar using Ag-50Cu-5Ga filler and reliable joints were obtained.There were Ag-rich phase,Cu-rich phase and a fine eutectic structure of Ag-based solid solution and Cu-based solid solution in the copper joints and the width of brazing seam is about 60μm.The joints of kovar alloy to copper after surface nickel plating was composed of AgCu eutectic phase,Ag,Cu,Cu2Ga and CuNi2 phase.The tensile strength was 167 MPa and 150 MPa,respectively.The tensile results of joints show that the joint strengths were equivalent to the traditional brazing filler metals.
文摘The influence of Mn on wettability and microstructure of low-silver solders was investigated. Mn degrades the wettability of low-silver solders, while the wettability of the Mn doping solders does not change with Mn content in a linear way. As a result of Mn doping, the cellular/dendritic β-Sn and the eutectic phase are refined. It indicates that Mn promotes the spontaneous and heterogeneous nucleation process of the solder alloys. The growth of intermetallic compound on the joint inter＇ace during soldering is also restrained. Aging experiment shows that Mn suppresses the growth of Cu3Sn and Cu6Sn5 layers at the joint interface.
