A recent alternative to sintering nanometric ceramics is Spark Plasma Sintering - SPS. This process permits the sintering at lower temperatures and short times producing materials with density near the theoretical density with small grain sizes. In this work alumina powder with well dispersed 5%vol addition of nanometric zirconia inclusions were obtained and sintered using SPS method by heating to temperatures ranging from 1250 to 1400 ºC and different holding times were applied to determine the best condition for obtaining dense material with minimal grain growth. The samples were characterized by apparent density measurement, high-resolution SEM, and microhardness. The results show microstructural evolution for different sintering temperatures and holding times and the effect of inclusions on the alumina matrix grain growth, which is related to the results of densification under SPS conditions. Using the SPS method it was possible to obtain samples with full density at 1300 ºC and holding time of 2 min with homogeneous microstructure, and microhardness near 22 GPa.
spark plasma sintering; alumina-zirconia; nanocomposites
