Study On Grinding Force And Surface Evaluation Technology Of 2.5D SiO₂/siO₂ Ceramic Matrix Composite

Fiber-reinforced ceramic matrix composites(FRCMC)are widely used in aeronautics and space applications due to their excellent corrosion resistance,high temperature resistance and excellent mechanical properties.Different from the machining of traditional single materials,it has been reported that the strong anisotropy and inhomogeneity of FRCMC causes many specific problems in machining.So it is an important issue to learn more and develop the grinding process of composites in the manufacturing industry.Based on 2.5D SiO2/SiO2 composite,this paper studies key technologies of grinding,such as the grinding force,damage mechanism and the surface microstructure.Through a series of principale analysis and experiments observision,we find some outstanding characteristics of this kind of composits influenced by fiber orientations.This paper analyzes grinding mechanisms of woven ceramic matrix composites and presents mathematical models of grinding force.According to structural characteristics of woven ceramic matrix composites,we creatively propose crack deflection index caused by interphase and fiber orientation to predict grinding force.Through a series of experiments,we investigate the relationship between grinding process and the grinding force.The paper studied the 3D micro-topographical measurement and valuation from a new perspective.Through a series of measuring experiments,we find that both starting position of measurement and sampling conditions affected on the measurement results.This paper recommends optimization measurement parameter values of sampling conditions and discusses the evaluation criteria of machining composites surface which is different from single homogeneous materials.It is difficult to evaluate and predict the mechanical surface quality of woven ceramic matrix composites due to their anisotropic and non-homogeneous structure.The present paper proposed a new method of evaluating grinding surface quality on composites by the study on surface waviness.Based on 2.5D SiO2/SiO2 composite,the research has some new discovery that the material enhanced fiber orientations play a key role in micro-topography of FRCMC grinding surface.So the surface topography can be predicted by woven fibers orientation.This paper also investigates surface properties and performances among machining surfaces in different directions.The present paper studies the influence of diamond wheel grinding process on surface micro-topography and properties of FRCMC.Through a series of experiments,we investigate the relationship between grinding process and the composites surface quality.And analyze characteristics of the material surface topography height,wave distribution and surface support properties in details.This paper employs the orthogonal design to optimize grinding process parameters,and also successfully model a critical condition to modify the surface characteristics.The research obtained can serve as a useful foundation and an important technical support on improving the processing quality of FRCMC.