| 摘要 |
PURPOSE:To facilitate the mechanical constrainability of the shape memory alloy, to stabilize the shape memory treatment therefor and to increase its productivity into high by subjecting an Ni-Ti series shape memory alloy having specified compsn. to pretreatment constituted of specified heat treatment. CONSTITUTION:As the pretreatment to shape memory treatment for an Ni-Ti series shape memory alloy contg. 50.1 to 53.8atom% Ni or total that of Ni and Ni-substituted elements and the balance substantial Ti, heat treatment of holding under heating to the temp. area of 350 to 550 deg.C for >=10min is executed. Or, in place of the above heat treatment, cooling is executed from the high temp. state for <=3hr at 550 to 350 deg.C or the alloy once cooled to <350 deg.C from the high temp. state is heated again to the temp. area of 350 to 550 deg.C and is held under heating in the above temp. area for >=10min. By the above heat treatment, a TiNi3 intermediate phase is formed in a hard TiNi mother phase of the alloy. In this way, the formability of the above Ni-Ti series alloy is improved, its mechanical constrainability is facilitated without exerting adverse influence on the effect of the shape memory treatment and the shape memory treatment can stably be executed with good productivity without damaging. |
