Study On Tool Wear And Its Inhibition Method In Precision Cutting Of Single Crystal Silicon

As a kind of hard brittle optical materials,single crystal silicon has a series of advantages,such as low density,anisotropy,low coefficient of thermal expansion,self-lubrication,a low and stable coefficient of friction.It is widely used in precision machinery,anti-missile systems,aerospace and other fields.However,because single crystal silicon has high hardness,brittleness and other characteristics,tools will cause chipping,groove wear and other problems during the cutting process.Wear resistance of single crystal silicon chip is high,it will cause severe wear of tools in the cutting process and directly influence the service life of the tools.These factors have restricted the further popularization and application of single crystal silicon.The paper started with the point of tool wear in cutting process of single crystal silicon,combined with silicon machining test,contrastively analyzed the tool wear processes conventional fixed cutting and swinging cutting.Studied the wear mechanism of two cutting methods and analyzed the reason why the tool wear slowed down in the process of swinging cutting single crystal silicon.Firstly,used the ultra-precision lathe tool to cut single crystal silicon in the way of single factor variables,analyzed the cutting force in the theoretical way.The cutting force was measured during the process,and the effects of cutting speed,feed rate,cutting depth and tool rake angle are analyzed.Secondly,the ultra-precision cutting experiments of single crystal silicon were carried out traditional way.Observed the wear morphology of different cutting distances,and then inspected the surface quality.Combined with the tool wear morphologies,tool material properties and other factors,to analyze the wear mechanism of single crystal diamond cutting tools.Using theoretical prediction model gets the lapse distance of single crystal diamond tools,and discussed about the influences of tool wear to the surface quality.Thirdly,because of the unitability of single point cutting and the limitation of machining ability,a swing-holder is necessary to reduce the wear rate of diamond tool.The holder is controlled by electronics without hydraulic pneumatic or other power sources,and it also has high-precision.The swing angle could be set between 15 °to-15° and reciprocate.It can make full use of the edge and extend the service life of diamond tool.Finally,carrying out the contrast experiments between ultra-precision swing cutting and fixed turning,the evolution of diamond tool wears after two cutting modes were observed and the wear mechanisms were analyzed.Base on the studying the mechanism of tool wear,the best cutting parameters could be found by the single factor experiments in the swing cutting.