Effects of Interface Wedge Angle in Metal Side on Bonding Strength in Ceramic to Metal Joint
This study was performed to clarify dependences of bonding strength on the interface wedge angle in the metal side of ceramic-to-metal joint. Each plate Si3N4 and Ni used for this experiment is produced by wire electric discharge machining. The geometric interface shape at the edge of the interface is characterized by wedge angle on both side of the ceramic and metal defined as a configuration angle between the free surface of each material and the interface. As the wedge angle of Si3N4 is a right angle, the wedge angle of Ni is set from 30° to 180°. Joint specimens were bonded at high temperature using braze metal of 0.05mm thickness under vacuum and cooled slowly. The tensile bonding strength of the ceramic-to-metal joint was evaluated to determine the optimum interface shape. The highest bonding strength appeared under identical interface conditions where the fracture pattern changed. This study provided a useful geometric interface shape to improve the tensile bonding strength of ceramic-to-metal joint.