An airtight joint between high purity Al2O3 and the alloy Kovar was obtained using a partial transient liquid phase(PTLP) bonding technique with Ni Ti filler.A sandwich structure was observed in the soldered joint two side faces of the sandwich were Ti2Ni and at the center was thick layer of Ti solid solution.Shear testing indicated that the joint strength increased with increase of holding time,although a relationship between strength and joining temperature was not observed.