A Research On Mechanisms And Mechanical Modeling Of Ceramics Based On Microstructure

Due to the high hardness,high wearing feature and high toughness,ceramics have been widely used in aerospace et al.fields.But a grinding process standard of ceramics has not been obtained as for the complex microstructure.Therefore,it hindered the automation of grinding process.In this paper a thinking process of ceramics grinding was proposed.From the process we can see,machinability evaluation is the key part.However,there is no unified and effective evaluation method.In previous studies,materials mechanical properties,grinding parameters and geometry features have been considered to evaluate machinability and some predictive modeling have been proposed.No allowance is made for direct effects of materials microstructure such as grain,porosity,binding energy et al.In order to optimize the predictive modeling,an influence of microstructure on mechanism and grinding force modeling was studied.First,as examples of crystalline ceramics and non-crystalline ceramics,alumina ceramics and fused silica ceramics were used in this investigation.A plane grinding experiment was conducted on a MK9025 numerical controlled machine.A series of cutting depth was obtained by changing grinding parameters and grinding forces were measured and outputted.Then,data of force was analyzed.The single grit force,the specific grinding energy and surface roughness as a function of undeformed chip thickness were observed.Therefore,the effects of crystallite and non-crystalline microstructure on grinding mechanism and predictive modeling were obtained.At last,a simulation analysis was conducted to prove a conclusion that the cutting depth and grain size of alumina have a big influence on grinding mechanism.The ABAQUS software and cohesive element were used to simulate the crack path.