期刊
ACTA MATERIALIA
卷 53, 期 13, 页码 3625-3634出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2005.04.019
关键词
Co-Ni; martensitic phase transformation; differential scanning calorimetry; X-ray diffraction; transmission electron microscopy
This study investigated the thermal behaviour of the fcc <-> hcp martensitic transformation of Co-Ni alloys. The transformation was found to be incomplete in both directions upon cooling and heating. Upon thermal cycling, the transformation, as detected by differential scanning calorimetry, diminished rapidly, indicating that the transformation was highly irreversible. Optical microscopic observation revealed that surface reliefs appeared on pre-polished surfaces upon forward transformation, but did not disappear upon the reverse transformation, implying that the transformation also exhibited mechanical irreversibility. The irreversibility is explained on the basis of multiple choice of crystalline shuffling along 1/6 < 112 > {1 1 1}(fcc) for the fcc <-> hcp transformation. These observations suggest that the fcc <-> hep martensitic transformation system in Co-Ni is not suitable for thermomechanical shape memory effect, which requires high reversibility of the transformation both crystallographically and mechanically. It is regarded that this rule is generic and applicable to other fcc <-> hcp transformation systems. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据