OXIDE DISPERSION STRENGTHENED UNDIRECTIONAL SOLIDIFIED NI-BASED ALLOY AND ITS MANUFACTURE

摘要

PURPOSE:To improve the high temp. strength of the subject alloy by dispersing specific amounts of oxide to a precipitation hardening Ni-based alloy having specific compsn. and subjecting said alloy to undirectional solidifying. CONSTITUTION:The grains of oxide (Y2O3, Al2O3, etc.), 0.3-5%, by weight, having 100Angstrom -3mu average grain size and stable in high temp. and the Ni alloy powder consisting of 12-25% Cr, 10-18% Co, 1-6% Ti, 1-6% Al, 2-5% Mo, 0.5-2.5% W, 0.05-0.2% C, 0.003-0.08% B and =2% Hf and the balance consisting of Ni are mixed. The mixed powder is heated to the melting temp. or above of said Ni-based alloy, is thereafter subjected to undirectional solidifying at 30-500mm/hr solidifying speed to obtain the desired oxide dispersion strengthened undirectional solidified Ni-based alloy. In the alloy, the high temp. strength can be obtd. at about =1000 deg.C.