Abstract
Effects of H_2-exposure, Ar-exposure and pure air-exposure at 0.1MPa at 800℃ for 24 h on tensile and bending mechanical properties at room temperature were investigated of a TiAl ally. By these exposures, both tensile and bending strength were decreased compared with the as-received not-exposed specimen. Polishing of the surface layer of the exposed specimens increased the strength to the almost same level of the as-received in the Ar-and pure air-exposures, while to the lower level in the H_2-exposure. It is found that the room temperature strength of the H_2-exposed is reduced by both the surface brittle layer and the interior brittleness.
