| 主权项 |
1. A Ti—Ni—Nb alloy device which comprises one of a Ti—Ni—Nb alloy and a Ti—Ni—Nb—X alloy, wherein X is at least one metal selected from the group consisting of Fe, Cr, V, and Co,
wherein transformation of said device is finished at a temperature difference smaller than 10° C. after a start of reverse transformation, wherein said Ti—Ni—Nb alloy comprises 46.5 to 50.5 at % Ti, 6 to 15 at % Nb, and a balance of 50 at % or less of Ni, wherein at least one of a shape memory treatment condition and a strain applied to the alloy device are changed with respect to portions of the device in a lengthwise direction thereof such that the Ti—Ni—Nb alloy device has a seamless structure with different reverse transformation temperatures in the respective portions thereof, wherein said shape memory treatment condition includes a shape memory treatment temperature and a shape treatment time, and wherein said alloy device has a strain ranging between 8% and 15% in terms of an elongation strain after a heat treatment so as to have a temperature difference, ΔT, smaller than said alloy having no strain in a temperature range between 4 to 10° C., said temperature difference being from a reverse transformation start temperature, As point, to a reverse transformation finish temperature, Af point. |
