Study Of Palstic Deformation Mechanism Of Nanocrystalline

Plastic deformation mechanism is one of the important directions in the field of nanostructure metallic materials; some models have been built to explain the plastic deformation mechanism of nanocrystalline metals. But vacancies and vacancy clusters are not involved in this area. So the core is to find other mechanisms except dislocations mechanism after discussions about the deformation details including structure evolution and different kinds of factors. In this paper the microstructure and defects of nanocrystalline were studied by x-ray diffraction and transmission electron microscopy. Contrasted between before and after deformed, we researched the similarities and differences of nanocrystalline microstructure and defects character, comprehensively analyzed the influence to the correlation factors during the deformation process. We principium revealed the vacancies disciplinarian during the deformation process of nanocrystalline. Vacancy formation energy was characterized as one of important physical quantities, and then set up the model of vacancy formation energy calculation. It was discovered that crystal lattice expansion as the decrease of grain size. Vacancy formation energy of nanocrystilline has size effect obviously less than 40nm in company...