Study On Ductile-brittle Transition Energy-based Model Of Single Crystal Silicon With Ultrasonic Vibration Cutting Method

Due to its unique physical and chemical properties,single crystal silicon is wildly applied in the fields of integrated circuits(ICs),micro-electromechanical systems(MEMS),advanced infrared optics and photoelectricity,including thermal imaging lenses,photovoltaic cells and so on.While single crystal silicon is used in aerospace and space exploration,the manufacturing of small-batch customized parts is the main production mode.However,due to the intrinsic characteristics,such as low fracture toughness,high brittleness,elastic modulus and hardness,single crystal silicon is one of the typical hard-brittle materials which is difficult to machine.Linear vibration cutting method is a promising technology which can machine the brittle materials and significantly enlarge the critical depth of cut.Predicting the critical depth of cut before the linear vibration cutting of single crystal silicon will effectively improve machining efficiency.However,in the linear vibration machining of brittle materials,the impact mechanism among the critical cutting depth and the nominal cutting speed needs to be comprehended.This paper has established a specific-cutting-energy model to predict the critical depth of cut in linear vibration cutting of single crystal silicon.For the proposed model verification,a series of cutting experiments were carried out on single crystal silicon workpieces.This paper focuses on the proposed energy-based prediction model of critical cutting depth at the ductile-brittle transition point in linear vibration cutting of monocrystalline silicon.The components of cutting energy consumption in ductile mode and brittle mode cutting process of monocrystalline silicon are analyzed theoretically and their mathematical models are established respectively.Then the function curves of specific cutting energy consumption of brittle mode and brittle mode with respect to the depth of cut are drawn by MATLAB~?,and then the two function variarion curves were analyzed.The predicted value of the critical cutting depth at the ductile-brittle transition point in linear vibration cutting of single crystal silicon was obtained.In order to verify the proposed energy-based prediction model,two groups of conventional groove cutting experiments and linear vibration groove cutting experiments were designed respectively.White light interferometer is used to observe and measure single crystal silicon after groove cutting.The measured values of critical cutting depth of single crystal silicon are obtained and contrasted with the predicted values.The outcomes show that the values of prediction are in accord with that of mearsurement,and the prediction model can well simulate the variation tendency of the mearsured values.The prediction error for the critical depth of cut is less than 10%.In conclusion,the proposed energy-based prediction model of critical cutting depth at the ductile-brittle transition point in linear vibration cutting of monocrystalline silicon is an effective numerical predictive model.The proposed model can play a guiding role in the linear vibration machining of monocrystalline silicon,and can be extended to predict the critical depth of cut for ductile-brittle transition of the other brittle materials.