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Microstructural stability and mechanical properties of Al2O3/Kovar 4 J34 joint vacuum brazed using Ag-5Cu-1Al-1.25Ti (wt%) filler metal

Journal Article


Abstract


  • The Al2O3 ceramic and Kovar 4 J34 alloy were effectively bonded by vacuum brazing by using an Ag-based filler metal with a composition of Ag-5Cu-1Al-1.25Ti (wt%). The typical interfacial structure of the Al2O3/Kovar 4 J34 joint brazed at 960 ��C for 10 min was determined as Al2O3/Ti3(Cu, Al)3O/Ag(s, s) + Cu(s, s) + disperse AlCu2Ti/Ti2Ni + TiFe2/Kovar. The brazing parameters were observed to have a decisive effect on the microstructure evolution and variation of the mechanical properties of the Al2O3/Kovar 4 J34 brazed joints. The maximum shear strength of the brazed joints could reach 150 MPa, and the failure primarily occurred in the ceramic substrate and Ti3(Cu, Al)3O reaction layer. Moreover, the microstructural stability of the Al2O3/Kovar 4 J34 brazed joints at elevated temperatures was also investigated. After thermal cycling at 600 ��C for 3 h, the interfacial structure of the brazed joint did not change obviously except for the thickening of the reaction layer, and the joint shear strength remained at 130 MPa. However, the average shear strength of the joint under the testing temperature of 600 ��C was reduced to 73 MPa, and the fracture propagated along the Ag matrix of the brazing seam due to the softening of silver.

Publication Date


  • 2021

Citation


  • Wang, J. L., Yang, Z. W., Wang, Y., Wang, D. P., & Li, H. J. (2021). Microstructural stability and mechanical properties of Al2O3/Kovar 4 J34 joint vacuum brazed using Ag-5Cu-1Al-1.25Ti (wt%) filler metal. Journal of Manufacturing Processes, 72, 553-564. doi:10.1016/j.jmapro.2021.10.057

Scopus Eid


  • 2-s2.0-85118577189

Start Page


  • 553

End Page


  • 564

Volume


  • 72

Issue


Place Of Publication


Abstract


  • The Al2O3 ceramic and Kovar 4 J34 alloy were effectively bonded by vacuum brazing by using an Ag-based filler metal with a composition of Ag-5Cu-1Al-1.25Ti (wt%). The typical interfacial structure of the Al2O3/Kovar 4 J34 joint brazed at 960 ��C for 10 min was determined as Al2O3/Ti3(Cu, Al)3O/Ag(s, s) + Cu(s, s) + disperse AlCu2Ti/Ti2Ni + TiFe2/Kovar. The brazing parameters were observed to have a decisive effect on the microstructure evolution and variation of the mechanical properties of the Al2O3/Kovar 4 J34 brazed joints. The maximum shear strength of the brazed joints could reach 150 MPa, and the failure primarily occurred in the ceramic substrate and Ti3(Cu, Al)3O reaction layer. Moreover, the microstructural stability of the Al2O3/Kovar 4 J34 brazed joints at elevated temperatures was also investigated. After thermal cycling at 600 ��C for 3 h, the interfacial structure of the brazed joint did not change obviously except for the thickening of the reaction layer, and the joint shear strength remained at 130 MPa. However, the average shear strength of the joint under the testing temperature of 600 ��C was reduced to 73 MPa, and the fracture propagated along the Ag matrix of the brazing seam due to the softening of silver.

Publication Date


  • 2021

Citation


  • Wang, J. L., Yang, Z. W., Wang, Y., Wang, D. P., & Li, H. J. (2021). Microstructural stability and mechanical properties of Al2O3/Kovar 4 J34 joint vacuum brazed using Ag-5Cu-1Al-1.25Ti (wt%) filler metal. Journal of Manufacturing Processes, 72, 553-564. doi:10.1016/j.jmapro.2021.10.057

Scopus Eid


  • 2-s2.0-85118577189

Start Page


  • 553

End Page


  • 564

Volume


  • 72

Issue


Place Of Publication