摘要
对Ni_2MnGa铁磁形状记忆合金的缺口试样,通过在微分干涉相衬显微镜下原位拉伸,研究了裂纹形核、扩展和马氏体相变以及塑性变形的关系．结果表明,拉伸时首先形成马氏体,当裂尖应力集中足够大时就会在裂尖产生局部塑性区,微裂纹易于沿马氏体界面形核,但也可在塑性区中形核．随载荷升高,微裂纹沿马氏体不连续形核,通过韧带剪切连接,从而导致裂纹扩展阻力也随裂纹扩展而增大．
The relationship between crack nucleation, martensitic transformation and plastic deformation of Ni2MnGa ferromagnetic shape memory alloy has been studied in situ using a differential interference contrast （DIC） microscopy. The result showed that martensites formed first during loading and then a plastic zone appeared when the stress was increased further. Microcrack initiated preferentially along the interface of martensite, but also initiated in the plastic zone . With increasing the load, microcracks initiated discontinuously along the martensites and connected through shear fracture of the ligaments.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第8期810-814,共5页
Acta Metallurgica Sinica
基金
国家自然科学基金50428101
