JPS6442184A - Manufacture of thermocouple - Google Patents

Abstract

PURPOSE:To obtain a thermocouple which has a high relative density and hence has excellent electrical and mechanical characteristics with a low cost as a whole by a method wherein the raw materials are tempered into fine uniform particles and kneaded with organic materials, injection-molded and sintered by debindering. CONSTITUTION:The material of a P-type thermoelectric element and the material of an N-type thermoelectric element each are tempered into approximately spherical fine and uniform particles with diameters of 2-5mum and kneaded with binder whose volume ratio to the thermoelectric materials is 40% to obtain soft mixtures. Then the kneaded mixtures each are injected into a mold which has at least two apertures from the respective ends and unified at a predetermined position in the mold. The injection molding is gradually heated to eliminate most of the organic materials in the molded unit. The debindered molding is heated at a high temperature and the temperature is maintained until the molded unit is alloyed with uniform components by the diffusion of the respective atoms and sintered. With this constitution, the relative density can be improved to 95%-97% as a whole and, moreover, by the uniform distribution of voids, a thermocouple which has a reduced resistance and can take out an electromotive force without attenuation electrically and which has an extremely high ductility mechanically can be obtained.