Sintered Al2O3 was brazed to AISI 8650 steel using a 67Ag-26Cu-5Sn-2Zr (wt.
%) brazing alloy. The microstructure of the brazement and the interfacial p
hase between the Al2O3 and brazement was investigated. The single ZrO2 laye
r with a monoclinic structure was formed by the migration of Zr in the molt
en brazing alloy to the Al2O3 surface, followed by a redox reaction between
them. Small Ag and Cu particles were present in the reaction layer. The re
mainder of the brazement formed a Cu-Ag eutectic alloy. Sn was homogeneousl
y distributed within the brazement so that Sn-contained compounds were not
formed within the brazement. The Al decomposed from Al2O3 diffused into the
residual brazing alloy and AISI 8650 steel. (C) 2000 Elsevier Science B.V.
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