Research On Micro-grinding Quality And Evaluation Of Friction And Wear Properties Of Chemically Modified Single Crystal Silicon

Hard and brittle materials are widely used in high-tech fields such as aerospace and microelectronics industries.The micro-grinding process is one of the main processing methods for micro structure and microparts of hard and brittle materials.The current micro-grinding of hard and brittle materials can easily cause machining damage at the edge of the micro-corner edge,such as cracks,chipping,and missing corners.This restricts the popularization and application of micro-grinding technology.In order to reduce cracks,chipping,missing corners and other processing damage,chemical machining methods is introduced into micro-grinding technology.This method combines force,heat,and chemical multi-energy complexes to weaken the mechanical action during material removal.Based on the above methods,this thesis develops the research work on the micro-grinding quality and the evaluation of friction-wear performance of chemically modified monocrystalline silicon.The chemical mechanical modification mechanism and conditions of monocrystalline silicon are analyzed.The effects of chemical modification conditions on the micro-grinding quality and friction-wear properties of monocrystalline silicon are discussed.The factors that affect the friction-wear properties of monocrystalline silicon are evaluated by the grey correlation method.This thesis mainly focuses on the following aspects:(1)The reaction mechanism of monocrystalline silicon under different modification conditions is analyzed.Precipitate content of silicon in different chemical modification fluids is detected by plasma inductive coupling method.The influence of the composition and pH of the acidic and alkaline chemical modification liquids on the chemical modification degree of the monocrystalline silicon is analyzed.(2)Monocrystalline silicon micro-grinding experiments are conducted.The effects of different chemical modification conditions,feed rates,and spindle speeds on the grinding quality of monocrystalline silicon edges are discussed.The average crack width is used as the evaluation index to analyze the influence of chemical modification conditions,feed rate,and spindle speed on the microgrinding edge damage scale.(3)Monocrystalline silicon friction-wear experiments are conducted.The diamond grinding block is selected as a friction pair.In the friction-wear experinment,chemical modification conditions,slip speed and load are considered as experimental factors.The coefficient of friction and cross-sectional area of wear scars of monocrystalline silicon are experimental indicators.Three factors and five levels of orthogonal test and single factor experiment are designed separately.By analyzing the friction and wear properties under various experimental conditions,the chemical modification of monocrystalline silicon induced by mechanical stress is studied.(4)The coefficient of friction and the cross-sectional area of the wear scar are defected and used as comprehensive evaluation indicators to evaluate the effects of chemical modification conditions,slip speed and load on the friction-wear properties of single crystal silicon by using the method of grey correlation,In summary,the edge grinding quality of monocrystalline silicon can be effectively improved in chemical modification.Under the condition of weak alkali chemical modification,better edge quality and friction-wear performance are obtained.Mechanical stress contributes to chemical modification of monocrystalline silicon.The research results provide experimental and theoretical basis for the chemical mechanical micro-grinding of hard and brittle materials.