Yc. Yoo et al., Microstructure and bond strength of Ni-Cr steel/Al2O3 joints brazed with Ag-Cu-Zr alloys containing Sn or Al, MATER SCI T, 15(11), 1999, pp. 1331-1334
Sintered Al2O3 was joined to Ni-Cr steel by the actise metal brazing route
with Ag-Cu-Zr brazing alloys containing Sn or Al. A single ZrO2 layer with
a monoclinic structure was formed at the Al2O3/brazement interface by the m
igration of Zr in the molten brazing alloy to the Al2O3 surface, followed b
y a redox reaction between the Al2O3 and Zr. The remainder of the brazement
formed a Cu-Ag eutectic alloy. Precipitates CuZr2 and Cu-Zr-Al were formed
in the brazements of the Ni-Cr steel/Al2O3 joints brazed with Ag-Cu-Zr all
oys and Al containing Ag-Cu-Zr alloys, respectively. On the other hand, no
precipitates were formed in the brazement of the Ni-Cr steel/Al2O3 joints b
razed with Sn containing Ag-Cu-Zr alloys. The Ni-Cr steel/Al2O3 joints braz
ed with Sn containing Ag-Cu-Zr alloys showed much higher fracture shear str
engths than those blazed with Ag-Cu-Zr alloys or Al containing Ag-Cu-Zr all
oys. MST/4329.