Microstructure and thermal conductivity of Si-Al-C-O fiber bonded ceramics joined to refractory metals

Abstract

We explore joining Si-Al-C-O fiber-bonded ceramics to Cu-clad-Mo using an Ag-Ti-Cu brazing alloy. A temperature of 900 °C and times in the range of 10–20 min are required to obtain sound joints irrespectively of the fiber orientation. The reaction layer is 1–2 μm thick and free of pores and defects. The thermal conductivity of the joined samples is well described considering that the metal and the ceramic are in series for thermal resistance. This implies that the joint is highly conductive and forms an almost perfect thermal interface between the two materials, confirming the quality of the obtained brazing layer.