Vacuum brazing ceramics to metals

Attention is given to the use in ceramic/metal joint brazing alloy of silver-copper composition that incorporates 2 percent Ti. This alloy allows one-step brazing, and wets superalloys and stainless steels without prior Ni plating of the substrate. Another alloy consisting of Ag-Cu-In-Ti has been developed which alloys at lower temperatures and allows step-brazing when used with Ag-Cu-Ti alloy. If the thermal expansion difference between metal and ceramic is large, brazing with a graded seal may be used; this minimizes joint stresses upon cooling to room temperature.