浮遊帯溶融されたMo, W, Taの二，三の性質

Abstract

The refining effect of floating zone melting on molybdenum, tungsten and tantalum were investigated from their mechanical properties and chemical analysis. Floating zone melted tungsten and molybdenum rods showed excellent bent ductility at room temperature. By the floating zone melting method, tungsten and molybdenum grew to single crystals rather easily, and their crystal orientations were almost near the (111) direction. By tensile tests, zone melted molybdenum and tantalum rods showed fracturs of the chiseltype break pattern, and no yielding was observed. Compression strain hardening exponents of the floating zone melted molybdenum and tungsten rods were smaller than those of the starting materials, but in the case of the tantalum rod, the strain hardening exponent of the zone melted part was somewhat larger than that of the starting rod. The resistance ratio of the zone melted molybdenum rod was 2.8×10−4 against 4.0×10−2 in the starting rod and 3.2×10−2 in the recrystallization zone.