Wetting, reaction, and interfacial microstructures in active metal joining of ceramics

摘要

Ag alloys containing Hf or Zr have been reacted under controlled conditions with sapphire, 96% and 99.6% alumina, and fused silica. The multiple alloy and ceramic combinations allow testing of the effects of composition and concentration of the active metal addition on interfacial reactions and microstructures. All alloys wet the ceramics after heating at 1100℃. The Ag/Zr alloys reacted more extensively than did the Ag/Hf alloys. Reaction products for the Ag/Hf alloys tended to remain at the interface; for the Ag/Zr alloys the products diffused into the alloy. The order of wetting and reaction tendencies with composition are opposite from what one would expect if they were controlled simply by thermodynamics of ideal reactions.