Nitinb shape memory alloy and preparation method therefor

A preparation method for a NiTiNb shape memory alloy, wherein the NiTiNb shape memory alloy has a relative density of 96%-99%, and the preparation method specifically comprises the following steps:

• (1) uniformly mixing a Ni source, a Ti source, and a Nb source to obtain a mixed powder material, wherein the Nb source is Nb powder having a particle size of −900 mesh to −500 mesh;
• an addition amount of the Nb source is such that Nb accounts for 9 at. % to 15 at. % of the mixed powder material;
• and an atomic ratio of Ni to Ti in the Ni source and the Ti source is (50.0-51.0):(49.0-50.0);
• (2) cold-press molding the mixed powder material to obtain an alloy green compact;
• and
• (3) sintering the green compact as follows:
• under a vacuum degree of 10−5~10−3 Pa, first heating to 580-620° C. at a rate of 5-10° C./min and holding for 0.5-2 h, then heating to 680-720° C. at a rate of 1-2° C./min and holding for 2-4 h, and then heating to 1,130-1,150° C. at a rate of 1-2° C./min and holding for 1-6 h, thereby obtaining a sintered sample, i.e., the NiTiNb shape memory alloy.