COMPOSITE STRUCTURE OF NIOBIUM-TITANIUM-HAFNIUM ALLOY MATRIX AND NIOBIUM-BASE METALLIC REINFORCEMENT

摘要

PURPOSE: To provide a metallic composite structure excellent in tensile strength and breaking strength at high temp. by using an Nb-Ti-Hf alloy of specific composition as matrix and incorporating, as reinforcement, strand-like structures for ductility strengthening, composed of Nb-base metal, into the matrix. ;CONSTITUTION: A lightweight Nb-Ti-Hf alloy of body-centered cubic structure, having a composition consisting of, by atom, 35-45% Ti, 10-15% Hf, and the balance Nb and having relatively low tensile strength at high temp., is used as matrix. A strand-like reinforcement with a size of at least 20 microns, which is composed of an Nb-base metal with similarly body-centered cubic structure, having lower oxidation resistance than the matrix metal but having high density and excellent in high temp. strength at ≥1000°C, is dispersedly incorporated into the above matrix by ≤5 vol.%. By this method, the metallic composite structure, which has a reinforcing ratio of at least ≥50% and usable at a temp. as high as ≥1400°C and in which the outside part is composed of the matrix metal alone and the other part is composed of the composite metal, can be obtained.;COPYRIGHT: (C)1993,JPO