Study on Nanoindent Defect Evolution and Elastoplastic Deformation Behavior of Single Crystal Copper in Aqueous
The plastic deformation law of single crystal copper in the nanoinding experiment of aqueous medium and the evolution of dislocation nuclei and defects were explored from the atomic scale.Using molecular dynamics methods,lambs are used to simulate the nanoindentation of single crystal copper in aqueous environment,observe the atomic transient images of the indenter during loading and unloading,and finally obtain the load-displacement curve of the indentation process and explore the elastoplastic deformation law.Ovito visualization software is used to observe the structure of the copper atom of the HCP lattice type of single crystal copper in the nanoindentation process by,analyze the four stages of the evolution of the internal dislocation of single crystal copper,and observe the growth of the shaped nucleus and emission behavior of the dislocation ring.To explore the similarities and differences in the evolution of nucleation between different dislocation rings,and to analyze the associative coupling effect of dislocation rings,the similarities and differences between the two under vacuum and aqueous media conditions are compared.The results show that during the loading process,the water molecules take away most of the energy of the plastic deformation of single crystal copper,resulting in a decrease in the type and scale of dislocation defects of single crystal copper;in the unloading process,due to the residue of water molecules,the surface of single crystal copper is rougher,and the deformation of the subsurface of single crystal copper is more serious.In addition,the evolution process between different dislocation rings is similar,but the greater the depth of pressure down the indenter,the more the nucleus time lag of the dislocation ring,and the smaller the scale of dislocation.It is concluded that in the aquatic environment,the type and scale of dislocation deformation of the material can be effectively controlled.
water environmentmonocrystalline coppernano-indentationmolecular dynamics simulationdislocation