REACTIVE SINTERING OF ZIRCONIUM CARBIDE BASED SYSTEMS

摘要

The high cost of commercial ZrC nanopowder has spurred the development of cost-efficient and low-energy approaches for carbide synthesis. Mechanical activation synthesis (MAS) by high-energy ball milling technology and reactive vacuum sintering was used to synthesize ZrC powder from zirconia (ZrO_2) at the low temperature of 1500°C.However, a major drawback for structural ZrC powder made from MAS was the relatively low fracture toughness, and difficulty ensuring adequate hardness and densification when vacuum sintered below 2000°C. ZrC combined with 20% weight molybdenum was sufficient to yield a cermet of 96.1% densification, hardness of 17 GPa, and fracture toughness of 5.23-6.08 MPa·m~(1/2). This present study was able to achieve a genuinely homogenous ZrC-Mo cermet in vacuum sintering temperatures not exceeding 1900°C.