Study On Machinability Of Ce-ZrO₂/CePO₄ Composite Ceramics

The machinability of ceramic materials, should be taken into account during the product design, the materials are often selected on the basis of machinability. Machinability can be applied to provide the basis for determining the optimum machining parameters, and to design ceramics with better machining characteristics by choosing the desired mechanical properties. This paper completely considered various influence factors of machinability, based on fuzzy comprehensive evaluation theory and digraph theory, the machinability of ceramic materials were evaluated with two methods. The machinability evaluation will be an important reference for determination of tools and machining parameters during ceramic machining processes.Based on the physical and mechanical properties of ceramic materials, fuzzy comprehensive evaluation principal in the fuzzy mathematics was applied to establish a model of machinability evaluation of ceramic materials. The borderline of machinability was fuzzy by reason of the membership function and the weighted average in the evaluation, variable weights was selected. The research results show that the machinability of ceramics can be evaluated accurately.Based on digraph theory in the graph, machinability attributes of the materials were taken as the nodes and the correlations between attributes were taken as the edges, the digraph model for machinability evaluation of ceramics was set up. According to the diagraph model, the machinability attribute matrix was constituted. Then machinability indexes of ceramic materials were calculated with permanent function and machinabilities of the ceramics were evaluated. Machinability attributes and their correlations can be taken into account simultaneously by digraph model. So, the machinability of ceramics can be evaluated correctly and completely by this method.In this paper, six composites consisting of CePO4 and zirconia were fabricated and measured. Then the ceramic materials were drilled, cut and ground. The machinability for machinable ceramics containing rare-earth phosphates was analysed with the material removal rates, grinding forces and SEM.The research results show that the proposed method evaluates machinability of ceramic materials according to property parameters analysis, machinability can be evaluated in advance of ceramics machining processes and replace the machining tests. Moreover, the method is easily and conveniently calculated with computer.