This is a typical example of a fine ceramic sintered compact for wear-resistant parts. High-speed sintering minimizes grain growth of the starting materials and provides sintered compacts with a very high relative density of 99% to 100% and, a high hardness grade of over 20GPa with few micropores or baking irregularities. Pressurized sintering allows for the direct sintering from powders to Near-Net-Shape dimensions by using ring or cylinder shape dies, eliminating the green compact forming process. Sintered parts have finished tolerances of 0.2 to 0.3mm, demonstrating the high accuracy and high density achieved by SPS. Sintering conditions were: pressure of 30 to 50MPa, sintering temperatures of 1400 to 1600 and temperature rise/holding time of 15 to 20 minutes.

Densities of ultrafine silicon carbide (SiC) powder of 99% purity not containing sintering additives by conventional processes has been limited to 92% or 93%. In this example, density reached over 99% of theoretical density, thanks to SPS ultrahigh-temperature sintering at a temperature of 2400℃ and with a temperature rise/holding time of only 7 minutes. This new technology delivers compacts with better mechanical properties than materials processed by conventional sintering methods; Vickers micro-hardness and fracture toughness were 28.6GPa and 4.7MPa/m0.5 respectively. No pores or grain growth were found; SEM observation of the fracture surface showed transgranular fractures that indicates strong inter-granular bonding.