PURPOSE: To obtain a dispersion-strengthened composite metallic body excellent in oxidation resistance at a high temp., by composing it of coating having a specified compsn. of Cr, Al, Ta, Y and Ni and a powder metallurgical Ni alloy base material having a specified compsn. contg. Cr, Al, fire resistant oxide or the like.

CONSTITUTION: By composing this alloy of a coating having a compsn. contg. 15 to 25% Cr, about 3 to 11% Al, ≤5% Ta, ≤1% Y, and the balance Ni, and an oxide dispersion-strengthened powder metallurgical alloy base material having a compsn. essentially contg. 10 to 35% Cr, 3 to 9% Al, ≤0.2% C, fire resistant oxide; the amt. effective for improving strength to 5%, ≤3% Ti, ≤10% W, ≤8% Mo, ≤8% Ta, ≤4% Nb, ≤20% Co, ≤4% Re, ≤2% Hf, ≤4% Fe, and the balance Ni, an Ni-Cr type mechanically alloyed material showing high oxidation resistance at high temps. exceeding about 2000 to 2200°F can be obtd.