Research On Tool Wear Mechanism And Suppression Technology For Ultra-precision Cutting Of Single Crystal Silicon

Single crystal silicon is widely used in aerospace,infrared detection,weaponry and other fields due to its advantage of good infrared transmittance,high refractive index,good dispersion,high melting point,good thermal conductivity,good material uniformity,low density,and stable chemical properties.However,single-crystal silicon is a difficult-to-cut material with high hardness and high brittleness.During single-point diamond cutting,the tool wear is severe problem and the tool life is extremely short,which greatly limits commercial application of single-crystal silicon.Therefore,the research on tool wear mechanism and tool wear suppression technology is highly desired and has been a hot topic in the field of ultra-precision machining for decades.This article has conducted exploratory research on these two aspects.Firstly,the tool wear behavior and mechanism of single crystal silicon ultra-precision cutting process were studied by experiments and simulation.Through the end face cutting experiment,the relationship between the feed rate,the quality of the processed surface,cutting force and the tool wear with increasing cutting distance was studied.Scanning electron microscope found that the form of tool wear is mainly groove wear and micro chipping.The mechanism of tool wear was analyzed through molecular dynamics simulation and experimental study.The diamond tool is graphitized and diffused during the cutting process,and the rough mechanical friction between the tool and the workpiece surface causes serious tool wear,which provides a theoretical basis for the tool wear suppression technology.Secondly,since lubrication has a great influence on ultra-precision cutting of single-crystal silicon,this paper discussed the lubrication effect of nanoparticle type and mass fraction.The relationship between tool wear and cutting force with cutting distance under nanoparticle lubrication is also studied.The principle of nano-particle lubrication to reduce tool wear is analyzed,which provides a method for improving tool life.Finally,the effect of ultrasonic vibration-assisted cutting coupled with nano-particle lubrication is studied and the effect of cutting speed and lubrication on tool wear is studied.The feasibility of cutting single crystal silicon by various methods was analyzed.The results in this paper is helpful to further understand the tool wear mechanism,improve the processing efficiency,and extend the service life of the tool in ultra-precision machining of the single crystal silicon.At the same time,it lays a theoretical foundation and a processing method that can be used for high-efficiency,high-quality ultra-precision machining of largediameter or complex curved single-crystal silicon optical components.