水素によるチタン焼結押出材の高強度発現機構

抄録

ABSTRACT
TiH₂ raw powders were directly consolidated by cold pressing, sintering and hot extrusion to fabricate pure Ti materials. The residual hydrogen content depended on the sintering temperature, and showed a significant effect on α/β phase transformation during hot extrusion. When 0.33 mass% hydrogen was contained in the sintered compact, α→β phase transformation occurred completely at extrusion temperature of 1073 K, and resulted in the formation of <0001>_α texture of the extruded Ti material. This texture was completely different from that of the conventional extruded Ti materials (<10 – 10>_α texture) with very few contents of hydrogen. The former indicated extremely high tensile strength (σ) of 959 MPa and enough elongation (δ) of 27.6 % compared to P/M extruded pure Ti materials with σ = 634 MPa and δ = 29.9 %.