Investigation of the Bonding and Working Processes in Metal-Ceramics using the New Fabricating Method

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Most of new advanced materials are lacking workability, so it is necessary to build up a method of forming into desired shapes, e.g. superconducting wires or shape memory alloy sheets etc.. This study relates to the methods of manufacturing of the materials with low workability, such as hard alloys, fine ceramics and intermetallic compounds. Properties of the joint interface and workability of the multi-metal billet or clad are discussed.The thin coating as an inner layr was made on the steel sheets using a vacuum ion beam deposition. Ti, Ag and Nb were deposited to examine the bonding, extrusion and wire drawing characteristics. The conpatibilities in metal-metal or -ceramic clads are investigated through the friction and shear bonding between core/sleeve by varying the diameter differences of them. Materials as the hard core are steels, Nb and some metal powder and ceramics. Copper and soft magnetic iron are used as softer sleeves.The interface of clad composites are investigated by optical and scanning electron microscopies and a profile meter in detail. The multi-metal billets are cold extruded, rolled and drawn to the composite wire products.The present results may be summarized as follows :1. Some of the metal coating between rolling sheets improved bonding qualities.2. The geometries of the multi-material billets, namely extrusion sleeve and core, can be designed so that the interface may become relevant to provide the bond strength with severe friction and shear stress.3. Consequently, the cold extrusion and wire drawing of the multi-material billet was sucsessfully performed up to areal reduction ratio of -10^5.