Comparison of Creep Behavior in Alumina Based Ceramics Densified by Spark Plasma Sintering and Hot Pressing

Spark plasma sintering (sps) method, as plasma activated sintering, is a method applicable for rapid sintering ofmetals and ceramics. owing to the advantage of rapid heating, the alumina ceramics obtained by sps have a grainsize and density comparable to those of hot pressed ones. the increase of densification rate may be related tosome difference in ion transport characteristics. this study describes creep behavior and deformation mechanismsof alumina based materials densified by sps, and somewhat comparison is made with hot pressing (hp) at hightemperature. pure alumina was densified by sps at 65 mpa (1200 ?c) and 45 mpa (1400 ?c) by hp. the grain sizeof the alumina hped was twice more than the grain size of the sample spsed. compressive creep tests in air wereperformed at different true stresses up to100 mpa and different temperatures (1200 ?c-1400 ?c). the grain growthwas found to be more active during creep of sps alumina than the creep of hp alumina. generally, the finenessof sps materials microstructure speeded up all processes related to diffusion. the ratio of dynamic to static graingrowth in spsed samples was twice more than hped samples during creep test.