Numerical Simulation Study Of Molecular Dynamics Of Two-body Nano-polished Single-crystal Copper

With the continuous development of modern processing technology,the requirements for the surface quality of workpieces have become higher and higher,and the traditional processing technology has been difficult to meet the requirements for the surface quality of workpieces by high precision equipment,so nanofabrication manufacturing technology has been called the focus of research in various countries.In this paper,the effects of processing parameters and crystal anisotropy on nanopolishing are investigated from the perspectives of internal material defects and damages,chips,polishing force,and dislocations through molecular dynamics simulations.The molecular dynamics model of two-body nano-polished single-crystal copper was established,and the simulation analysis revealed that the increase of polishing speed would reduce the generation of internal molding dislocations in the workpiece and make the chip atoms generated in polishing gather,while the increase of polishing depth would increase the defects inside the workpiece and at the same time would increase the chip atoms generated in polishing,and the deeper the polishing depth,the more chip atoms gathered and the less diffusion to the ends of the abrasive grains.With the increase of polishing depth,the tangential force is greater than the normal force,different polishing speed and polishing depth of the line dislocations generated mainly Shockley incomplete dislocations,other types of line dislocations with polishing speed and polishing depth changes constantly,polishing speed increases will reduce the polishing process Stair-rod line dislocations and Perfect line dislocations generated,and polishing The increase of polishing speed will reduce the generation of Stair-rod line dislocation and Perfect line dislocation during polishing,while the increase of polishing depth will increase the generation of various types of line dislocation.Three different polishing directions were set up to polish each crystal face of single crystal copper,so as to study the effect of crystal anisotropy on polishing,and the results showed that:(2 1 2)crystal face produced the least chip atom side flow,chip atoms are the most aggregated,(1 1 0)crystal face had the most serious chip atom side flow but was not dispersed,(0 1 0)crystal face had the most dispersed chip atoms,and the most damage occurs at the entrance when polishing the(0 1 0)crystal face along the[1 0 0]crystal direction;the anisotropy of the crystal during polishing has a greater effect on the normal force than the tangential force,which also makes the severity of the complex defects inside the single crystal copper and the direction of expansion vary,and the effect on the dislocations is also different,these three crystal surfaces mainly produce Shockley incomplete dislocations during polishing,and other kinds of dislocations appear less,The dislocation defects inside the workpiece on the(0 1 0)surface are more serious than those inside the other two surfaces,while the dislocation defects inside the workpiece on the(1 1 0)surface are more serious than those inside the(2 1 2)surface.