The Evolution of Nanoindentation Test on Machining-induced Surface of Single-Crystal FCC Copper
The physical properties of new machining-induced generated surface depend on the performance of initial-defect surface and deformed layer in subsurface of bulk material.In this paper,three-dimensional molecular dynamics (MD) simulations of nanoindentation tests are preformed on the single-point diamond turning of single-crystal copper with a comparison with that of pristine single-crystal FCC copper.The simulation results indicate that the nucleation of dislocations in the nanoindentation test on machining-induced surface and pristine single-crystal copper is different.The dislocation embryos are gradually developed from the sites of homogeneous random nucleation around the indenter in the pristine single-crystal specimen,while the dislocation embryos derive from the vacancy-related defects distributed in damage layer of subsurface beneath the machining-induced surface.These results provide the nature of that the hardness of the machining-induce surface is softer than that of pristine single-crystal copper.Then,the nanocuttings are performed along different crystal orientations on the same crystal surface.It is shown that the crystal orientation directly influences the dislocation formation and distribution in the machining-induced surface.The crystal orientation of nanocutting is further verified to affect both surface pile-up and residual defect generations that are important in assessing the change of mechanical properties after nanocutting.
Lin Zhang Hongwei Zhao Yihan Yang Zhichao Ma Hu Huang
School of Mechanical Science & Engineering, Jilin University, 130025, R P China
国际会议
中国微米纳米技术学会第14届学术年会、第3届国际年会暨第6届微米纳米技术“创新与产业化国际研讨与展览会(CSMNT2012 & ICMAN2012)
杭州
英文
1-13
2012-11-04（万方平台首次上网日期，不代表论文的发表时间）