Investigation Of Multiscale Numerical Simulation Of UltraPrecision Cutting Technology

With the development of scientific technology, the study of ultraprecision manufacturing technology (UMT) has attracted many people's attention. We should adopt new method to engage in the study of micromechanism of UMT because the experiment whether based on ultraprecision machine or scanning probe microscope (SPM) is costly and wasting time. Through many scholar's endeavor, computer simulation technology has achieved well rounded theoretical foundation, on the other hand, with the development of superthread technology, streamline technology and distributed computation technology, the computational ability of PC has been greatly improved. Considering present condition of my laboratory, I carried out computer simulation of micromechanism of materials removal process and indentation contact behavior. In the case of metal manufacturing technology, the type of burr has been greatly depended on material's brittle/ductile property. In the case of manufacturing brittle material, it maybe cracked abruptly at the end of workpiece which may impact the tool and then decreased its life. Today, materials used in the simulation are all been assumed as ideal crystal without any defects which is differentiated with the reality. The author conducted simulation of defect materials manufacturing process to investigate the effect of defect on the manufacturing process. The value of cutting force in the case of manufacturing ideal crystal is two times that of manufacturing defect material. This implies that the defect degrade the strength of materials and the power needed in the manufacturing process. In the case of UMT, as cutting process has occurred in the local area adjacent to the tool tip, the wear mechanism must differentiate with macroscopic world. This paper constructed second generation simulation model where the tool is considered as elastic/plastic body and carried out the simulation about tool diffusion wear. Of all affecting factors, the depth of cut has dominating status while the anisotropy of crystal has little effect. This phenomenon implies that the diffusion between tool and workpiece is a chemical process and depended on the chemical similarity. Metal manufacturing technology is a process contains multiscale coupling phenomenon where fracture of atomic bond in the microscopic area will lead to the material removal in the macroscopic area. The author constructed ultraprecision manufacturing multiscale coupling model where the continuum mechanics is adopted in the micron scale and molecular dynamics is adopted in the local area around tool tip. Subsequently, the author conducted simulation and achieved satisfactory effect.