OXIDE DISPERSION STRENGTHENED TYPE NI-BASE ALLOY AND ITS PRODUCTION

摘要

PURPOSE:To obtain an Ni-base alloy excellent in heat resistance, thermal shock resistance, creep strength, and fracture life by hat-working a powder of an oxide dispersion strengthened type Ni-base alloy prepared by a mechanical alloying method and then growing crystalline grains by means of heating at the specific temp. CONSTITUTION:The crystalline grains of refractory metal oxide, such as Y2O3, and pure metal, such as Ni and Cr, are put into a high kinetic energy type ball mill, pulverized, and mixed by means of mechanical alloying, by which a uniform metal mixture of pulverized powder having a composition consisting of, by weight, 18-40% Cr, 5% Fe, 5% Al, 5% Ti, and the balance Ni is prepared. This powder mixture is subjected to hot working, such as hot extrusion, and to heating up to =1300 deg.C to undergo crystalline grain growth, thereby a secondary recrystallization structure in which the mean value of the aspect ratios of crystals is regulated to =10 can be formed.