颗粒材料在辊压振动磨中的结构演变研究

为了研究金属颗粒材料在力学场的结构演变及相应能量转换,在干法室温常压状态下,用辊压振动磨制备了晶粒尺寸在20～30 nm的超微颗粒,根据位错理论和点阵几何学,研究了锌超微颗粒在研磨过程中的尺度和结构演变.研究表明,在研磨过程中,锌颗粒的微结构和能量转换发生周期性变化.随着能量的不断导入,晶体总是在不同的能量状态下达到新的平衡,颗粒不断细化,势能不断提高,晶体颗粒储存的总能量态不断上升.在一定条件下应变和位错可以相互转换,但应变和位错的转化需要一定的积累周期.

Structure evolvement of powder by dry roller vibration milling at room temperature

The nanostructure evolution and microscope energy conversion via dry roller vibration milling was studied based on XRD analysis and dislocation theory.The zinc particles of 20~30 nm were prepared by dry roller vibration milling at room temperature,and their grain size and structural evolution in the milling process were analyzed via dislocation theory and lattice geometry.It is found that the response of zinc crystal structure to mechanical force is direction-selective.In the initial stage of milling,stacking fault governed the material deformation.However,the reducing of grain size is always accompanied by the increase of micro-strain and dislocations in the material.As energy imports,the crystal particles in different energy state always goes to new balance,the grain size decreases and the potential energy increases.Under certain conditions,strain and dislocation could be conversion,resulting in grain refinement,but a certain milling period was required for the accumulation and conversion of the strain and stacking fault.