Research On Development And Micro-grinding Performance Of Chemical Mechanical Micro-grinding Tools

The application and demand of the micro-parts with silicon-based and hard-brittle materials are expanding rapidly in cutting-edge industries such as aerospace,biological engineering,microelectronics industry.Meanwhile,the requirements on functional structure,surface quality,dimensional precision and service performance of these micro-parts are constantly increasing.Compared with MEMS manufacturing technology,micro-grinding technology has incomparable advantages in processing these micro-parts.However,due to the characteristics of silicon-based and hard-brittle materials and the performance of current micro-grinding tools,there are plenty of problems with micro-grinding technology,such as severe brittle fracture,poor surface quality and short life of micro-grinding tools.Therefore,chemical mechanical micro-grinding technology was proposed to manufacture the micro-parts with silicon-based and hard-brittle materials.Chemical mechanical micro-grinding tools with soft abrasive were fabricated,and the grinding performance of these micro-tools was evaluated and studied.This paper aims to improve ground surface quality and reduce the occurrence of brittle fracture through chemical and mechanical recombination action,so as to realize the precision machining of micro-parts with silicon-based and hard-brittle materials.The specific work is as follows:(1)The wear mechanism of commercial diamond micro-grinding tools and the effect of micro-grinding tools wear on surface roughness and average edge chipping width were analyzed.It is pointed out that the micro-grinding technology with diamond micro-grinding tools has some defects such as poor grinding quality and serious edge fracture.And chemical mechanical micro-grinding technology was proposed.(2)The physical and chemical properties of monocrystalline silicon,a typical silicon-based hard brittle material,were analyzed.The CeO₂micro-grinding tools with different ingredients were designed by orthogonal test method,the production process of the micro-grinding tools was developed,and their dressing method was determined.(3)The grinding performance of the micro-grinding tools with different specifications was analyzed and compared,and the effect of each ingredient on the grinding performance was analyzed and discussed with material removal rate,grinding ratio and surface roughness as the evaluation indexes.The results show that the removal way of monocrystalline silicon in chemical mechanical micro-grinding was ductile removal mode,and the grinding quality improved significantly.The grinding performance of the micro-grinding tools was evaluated comprehensively through gray correlation analysis method.It was verified that the optimized the formula of micro-grinding tools obtained better grinding performance.(4)Confocal Raman microscope and X-ray diffraction were used to detect the chemical composition of ground surface of monocrystalline silicon and wear debris,respectively.The solid-phase chemical reactions among abrasive,surfactant and monocrystalline silicon were analyzed,and the mechanism of chemical and mechanical recombination action was discussed in the process of grinding monocrystalline silicon,then the material removal model of chemical mechanical micro-grinding was established.The results show that chemical mechanical micro-grinding can improve effectively surface quality and reduce the occurrence of brittle fracture,the removal way of monocrystalline silicon was ductile removal mode,thus the damage to the material was minimal.The research results provide the experimental and theoretical basis for manufacturing micro-parts of silicon-based and hard-brittle materials in chemical mechanical micro-grinding.