1. Introduction
The deformation and fracture behaviors of structural materials
are always the main aspects for its performance.Preliminary
research to reveal the deformation and fracture mechanism generally accomplished via a comprehensive understanding of macroscopical deformation features, fractographs and some static
mechanical properties such as tensile strength and fracture toughness [1–5]. With the development of materials science and electron microscopy,a real-time and high resolution observation
of the deformation and fracture process in materials,especially for
them with in micro-nano scales,becomes available and increasingly receives widespread attentions [6]. In the past few decades,
by means of in situ straining transmission electron microscopy
(TEM) methods and related computer simulations,many researchers focused on the deformation and fracture behaviors of pure
metals [7–14], metalli calloys [7,15–17] and nanommaterials (including nanocrystalline [18,19],