Two-way shape memory properties of a Ni-rich Ti-Ni alloy aged under tensile-stress
Two-way shape memory properties of a Ni-rich Ti-Ni alloy aged under tensile-stress
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DOI：
10.2320/matertrans1989.38.514
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发表时间：
1997-06-01
期刊：
影响因子：
--
通讯作者：
Saburi, T
中科院分区：
文献类型：
--
作者：
Fukuda, T;Deguchi, A;Saburi, T
研究了“全方位（双向）形状记忆效应”的强度以及利用这一效应所能获得的工作。所使用的合金是Ti-51 (at%)Ni合金。为了使Ti3Ni4析出物的颗粒排列整齐，在不同的拉伸应力下，在773 K下时效6 ks。对这些老化试样进行了几种不同拉伸应力（sigma(Test)）下的热循环试验。在适当的拉伸应力下时效的试样与B2—>23R相变相关，总收缩率随着σ的增加而减小（试验）。由于这种收缩，试样在外部做功：当sigma（Test）在50到100 MPa之间时，这种做功最大。随着σ (Test)的增大，试样的B2—B19′相变起始温度逐渐降低。与后期R—>Br19′相变有关的是，σ (Test)低于50 MPa时时效试样收缩，大于50 MPa时时效试样伸长。只要重复B2R转化，试样中就不存在不可恢复的应变，但重复B2RB19’转化时，试样中就存在不可恢复的应变。
The strength of the ''all-round (two-way) shape memory effect'' and the work we can gain by using this effect were investigated. The alloy used was a Ti-51 (at%)Ni alloy. In order to align particles of Ti3Ni4 precipitate, plate-shaped specimens were aged at 773 K for 6 ks under several different tensile-stresses. Thermal cycling tests under several different tensile-stresses (sigma(Test)) were made on these aged specimens. Specimens aged under an appropriate tensile-stress shrink in association with the B2-->23R transformation and the total shrinkage decreases with increasing sigma(Test). Due to this shrinkage, the specimens do work on the outside: this work is the largest when sigma(Test) is between 50 and 100 MPa. The B2--B19' transformation start temperature of these specimens decreases as sigma(Test) increases. In association with the later R-->Br19' transformation, the aged specimens shrink when sigma(Test) is below 50 MPa, and elongate when it is above. Unrecoverable strain does not remain in the specimen as long as the B2R transformation is repeated, but it does when the B2RB19' transformations are repeated.