Joining of silicon carbide using MgO-Al2O3-SiO2 filler

Pressureless sintered SIC specimens were joined using MgO-Al2O3-SiO2 (MAS) filler. MAS filler showed excellent behaviour of wetting on SIC substrate a bove 1480 degrees C, and the wettability was much influenced by the joining atmosphere. The joining was carried out at 1500 and 1600 degrees C for 30 min in Ar atmosphere. The flexural strength of the joined specimen showed 3 42-380 MPa up to 800 degrees C. However, the flexural strength of the joine d specimen decreased to about 80 MPa at 900 degrees C due to softening of t he joint interlayer. The results of the XRD and WDS showed that the reactio n between SIC and the MAS filler produced the oxycarbide glass. (C) 1998 Kl uwer Academic Publishers.