A gradient nano/micro-structured surface layer on copper induced by severe plasticity roller burnishing

作者：Zhao Jing^*; Xia Wei; Li Ning; Li Feng lei

来源：Transactions of Nonferrous Metals Society of China, 2014, 24(2): 441-448.

DOI：10.1016/S1003-6326(14)63080-6

• burnishing
• pure copper
• gradient nano/micro-structure
• surface nanocrystallization

In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing (SPRB) and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100 mu m in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries (LAGBs). The coarse grains are refined into the few micro-sized grains by dislocation activities; deformation twinning was found to be the primary form for the formation of submicron grains; the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.

• 出版日期2014-2
• 单位华南理工大学