Kiyoshi Tamura

Production of Cu/Fe clad strip by powder rolling

To attempt a direct production of Cu/Fe clad strips from the powder materials, several factors in the rolling process, by using a newly designed hopper, were investigated, and also mechanical properties of clad strips fabricated in various conditions were examined.The results obtained were summarized as follows:(1) With decreasing the tip angle and height of a separator and particle size of powders, the asperities of Cu/Fe strip boundary became smooth.(2) Because of setting the separator in the hopper, the powder head gave no effect to the thickness and density of strips.(3) Effects of the roll-speed and roll-gap on the thickness and density of strips were similar to those in the rolling for single powders.(4) The tensile strength of sintered, cold rolled and annealed strips was of 28 kg/mm2, which was about 6 times as strong as that of the strip as-sintered at 1000°C.

Fabrication of MoSi 2 Base Heating Element by Slip Casting Process

In order to produce MoSi 2 base heating element by slip casting process, casting variables made clear, subsequently several physical and mechanical properties of the specimenss obtained from optimum casting conditions were investigated. Results were summarized as follow ;1) Polyvinyl alcohol was used as the additive agent and the optimum amount of it was. 1 w.t. %.2) Castability was best achieved with the viscosity in the range of 1000-1800 c.p., pH4.05 and water to metal ratio 0.180.3) Release difficulties from the plaster mold was overcome by film technique, using sodium alginate solution.4) Transverse rupture of green specimen was 0.55 kg/mm2, which showed sufficient green strength for handling purposes.5) Sintered density in Argon for 6 hr, at 1600°C, was 5.55 g/cc.6) Linear shrinkages of sintered specimens were in the range of 12.1-12.7%.7) Electrical and mechanical properties of sintered specimens produced by slip casting showed considerablly lower values than that of hot-pressing or coldpressing sintering.