JOINED PRODUCT OF CERAMIC MEMBER TO METAL MEMBER

摘要

PURPOSE:To allow to manifest good joining strength in a wide temperature range by constituting the subject jointed product from a ceramic member shaft portion and a cylindrical portion prepared of a metal member joined to the cylindrical portion and reducing the stress caused by the joint near the opening end portion of the cylindrical portion. CONSTITUTION:For example, a Si3N4 round bar 1 having an outer diameter of 12mm and a metal shaft 2 made of Incolloy 903 and having a cylindrical portion with an inner diameter of 12.4mm and a depth of 20mm are prepared. An electroless Ni plating is applied to the inner surface of the cylindrical portion of the shaft 2 so as to improve the wettability of the inner surface with a brazing material and the round for 1 is inserted into the shaft 2. The high melting point brazing material (BNi3)4 is charged into the portion up to a depth of 15mm in a space 5 between the round bar 1 and the shaft 2 under a prescribed condition in a vacuum over. A low melting point brazing material (BAg8)3 is subsequently charged into the remaining 5mm in the space near the opening portion of the shaft 2 under a prescribed condition in a vacuum over to provide a joined product. The cantilever flexural strength of the joined product at room temperature is approximately 25 times that of the jointed product in which the high temperature brazing material is charged into all portion of the space 5.