Fabrication and properties of machinable porous ZrO2f/Y2SiO5 nanocomposites prepared by a simple method

Novel ZrO2-fiber-reinforced porous Y2SiO5 ceramic nanocomposites were fabricated by a simple pressureless sintering process. Y2SiO5 nanoparticles were prepared by a sol-gel method, and the effects of sintering temperature and ZrO2 fiber content on the microstructure, thermal properties, and mechanical properties of the porous Y2SiO5 nanocomposites were studied. The mechanical properties and thermal conductivity of porous ZrO2f/Y2SiO5 nanocomposites were improved substantially with the introduction of ZrO2 fibers. Compared with the specimens without added fibers, the composites with 10 vol% ZrO2 fibers exhibited the optimum strengthening effects, including a high bending strength (i.e., 65.7 MPa), a low thermal conductivity (i.e., 0.55 W/(m·K)) and good machinability. The present work provides a simple procedure for improving the toughness and thermal insulation characteristics of porous ceramics.