Study On NiTi Alloy Nanometric Cutting By Molecular Dynamics Simulation

With the development of science and technology and the progress of society,the requirements for the processing accuracy of products are becoming higher and higher.Ultra-precision processing integrates a variety of technologies,which is a necessary means for obtaining high-precision products.As an important field in ultra-precision machining,ultra-precision cutting is a complex new technology.Because the thickness of the cutting is nano-scale,it is also called nano-cutting.Unlike traditional cutting,in nano-cutting,the tool and the workpiece are regarded as a collection of atoms or molecules.The cutting process essentially shows the discrete phenomenon of atoms,so the nano-cutting process needs to be carried out from the perspective of molecules or atoms.the study.However,the experimental research at the atomic scale is costly and requires severe experimental conditions.Therefore,molecular dynamics has become an inevitable choice for effective research on nano-cutting.Because of its good shape memory effect and super elasticity,NiTi shape memory alloys are used in important fields such as aviation and medical treatment.Therefore,the processing accuracy of NiTi shape memory alloy components is very high.In order to understand the nano-cutting mechanism of NiTi shape memory alloy,and thus save the cost of nano-cutting;this article uses molecular dynamics method as a research method,focusing on the nano-cutting mechanism of NiTi shape memory alloy.Based on the molecular dynamics simulation of nano-cutting under different cutting conditions,find out the influence of different cutting parameters and different initial temperatures on the cutting process of NiTi shape memory alloy.The main research contents are as follows:1.According to the existing molecular dynamics research of nano-cutting,combined with the martensitic transformation characteristics of NiTi shape memory alloy;select the currently widely used 2NN-MEAM potential function of Ni-Ti binary alloy based on next-nearest neighbor to establish Molecular dynamics model of NiTi shape memory alloy nano-cutting.2.Through the analysis of the cutting force,the atomic structure of the workpiece and the temperature of the workpiece in the nano-cutting process of the NiTi shape memory alloy,the cutting mechanism of the NiTi shape memory alloy is obtained.3.Based on the molecular dynamics method,the cutting process under different cutting conditions was simulated,and the changes of NiTi shape memory alloy during the cutting process under different cutting parameters(cutting depth,cutting speed,tool rake angle)and different initial temperatures were compared and analyzed.The characteristics of the cutting force,the atomic structure of the workpiece and the temperature of the workpiece during the cutting process are analyzed.Provide a theoretical basis for the actual nano-cutting of NiTi alloy,so as to achieve the purpose of reducing processing costs.