A micro-electromechanical system (MEMS) based technique is demonstrated for in situ transmission electron microscopy (TEM) measurements of stress relaxation with simultaneous observation of the underlying plastic deformation processes. True activation volumes are determined from repeated stress relaxation transients and thus provide a signature parameter of the governing mechanisms of plastic deformation. The technique is demonstrated with 100 nm-thick ultrafine-grained gold microspecimens under uniaxial tension. True activation volumes of approximately 3–5b³ (where b is the Burgers vector length) are obtained for tensile stresses ranging from 200–450 MPa. Grain boundary-dislocation interactions are observed via in situ TEM during stress relaxation measurements. The miniaturization of stress relaxation tests inside the TEM provides unique opportunities to characterize the plastic kinetics and underlying mechanisms in ultrafine-grained and nanocrystalline materials.

中文翻译：

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原位TEM测量超细晶粒金的活化量

演示了一种基于微机电系统（MEMS）的技术，该技术可用于应力松弛的原位透射电子显微镜（TEM）测量，同时观察潜在的塑性变形过程。真实的激活体积是由反复的应力松弛瞬变确定的，因此可提供塑性变形控制机制的特征参数。在单轴张力下用100 nm厚的超细金显微样品证明了该技术。对于200-450 MPa范围内的拉应力，可以获得大约3–5 b ^3的真实激活体积（其中b是Burgers矢量长度）。通过原位观察到晶界-位错相互作用应力松弛测量期间的TEM。TEM内部的应力松弛测试的小型化提供了独特的机会来表征超细晶粒和纳米晶材料的塑性动力学和潜在机理。