Ceramic-containing bodies can be bonded to other ceramic-containing bodies, or to metals or metal-containing bodies, by way of an aluminum-silicon brazing alloy. Such alloys feature high thermal conductivity and a melting range intermediate to Cu—Sil and Au—Si. By depositing a layer of silicon or aluminum, e.g., by vapor deposition, onto a surface of the ceramic-containing body, the formation of deleterious intermetallic phases at the brazing interface is avoided. This technique is particularly useful for joining reaction-bonded silicon carbide (RBSC) composite bodies, and particularly such composite bodies that contain appreciable amounts of aluminum as a metallurgical modification of the residual silicon phase. When the RBSC body contains minor amounts of the aluminum alloying constituent, or none, the metallization layer is not required. The resulting bonded structures have utility as mirrors, as packaging for electronics, and in semiconductor lithography equipment, e.g., as electrostatic chucks for supporting a silicon wafer during the lithography process.