Joining of ceramics to aluminum using Al-Mg and Al-Si alloys as fusible insert

Joining of aluminum (A1100) and four kinds of ceramics, Si3N4, SiC, Al2O3 and PS-ZrO2 (partially stabilized), was attempted by using Al-Mg and Al-Si alloys as fusible insert. Effects of insert composition and joining parameters, such as temperature, time, pressure, cooling rate and amount of insert, on the bond strength were investigated. The results obtained are as follows: (1) Both aluminum alloys worked successfully on the joining, and relatively high bond strength was obtained at the compositions, 5-20wt%Mg and 5-10wt%Si. (2) Joining at temperatures below 878K using the Al-Mg alloy insert, however, gave rise to high thermal stress, which decreased the bond strengths of Al2O3 and SiC remarkably. (3) A use of Al-Si alloy insert can be recommended when thermal stress becomes a serious problem. (4) Al-10wt%Mg alloy can be recommended as suitable insert for Si3N4 and SiC, and Al-5wt%Si alloy for PS-ZrO2 and Al2O3. (5) The following measures are effective to reduce the thermal stress in use of the Al-Mg alloy insert; i) to minimize the amount of the insert, ii) to increase joining temperature and/or time, and iii) to decrease the rate of cooling after joining.