USEFULNESS OF SPARK PLASMA SINTERING ON DENSIFICATION AND MECHANICAL-PROPERTIES OF ALUMINA WHISKER ZIRCONIA COMPOSITES

Zirconia (3 mol% Y2O3) matrix composites reinforced with 20 vol% alpha-alumina whiskers were prepared by spark plasma sintering (SPS) at 1200 to 1500-degrees-C under 30 MPa for a short holding time of 5 min. The room temperature mechanical properties were measured. The SPS brought about dense alumina whisker/zirconia composites at a sintering temperature lower than that in the hot-pressing process. The composites obtained by SPS had strengths, hardness and fracture toughness higher than those by hot-pressing under the same sintering temperatures. The zirconia matrix grains in the composites prepared by SPS grew larger than those by hot-pressing.