Molybdenum tungsten or tantalum wire contg second component - made from sintered blank with surface coating to aid deformation

摘要

In mfg. wire, where the cross-section of a blank is reduced by deformation, prior to deformation the blank is used as a core in a tough coating which is removed after deformation. The core pref. consists of 94-100 vol. % of a component (I) contg. 0-6 vol.% of a second component (II) forming a dispersion, and the coating is pref. made of component (I) which is esp. Mo, W or Ta. The second component (II) is pref. an oxide, carbide, boride or nitride of Ti, Zr, Hf, Cr, V, Nb, Mo, W or Ta, and the coating pref. has a thickness between 0.2 mm and 0.5 times the core dia. Prevents the formation of surface cracks or fissures during the deformation.