Preparation of machinable Ce–TZP/CePO4 composite ceramics by liquid precursor infiltration

A novel process has been used to fabricate Ce–TZP/CePO4 composite ceramics: namely infiltrating CePO4 liquid precursor into Ce–TZP porous ceramic. Sintered Ce–TZP ceramic preform with 35 vol.% open pore volume was developed by adding graphite 30 vol.%. The Ce–TZP/CePO4 composite ceramics containing different CePO4 contents were obtained by infiltration and pyrolysis cycles. The machinability and mechanical properties of these materials were investigated. Results show that the Ce–TZP/CePO4 composite ceramics can be cut and drilled using conventional tungsten carbide metal-working tools. Measurement of normal grinding force was used to compare the ease of machining in these materials. The machinable Ce–TZP/CePO4 composites containing a range from 2.3 to 7.5 vol.% CePO4 has good machinability as well as maintaining outstanding mechanical properties. The relation between microstructure and mechanical properties of the materials was discussed.