Fundamental Study of the Sintering Kinetics of Refractory Compound Phases at High Pressure and High Temperature

摘要

The work was divided between two aspects of high pressure hot pressing. The first phase involved a study of the problems associated with fabricating crack free compacts of TiB2 by high pressure hot pressing. In addition, the bend strength and fracture mode of high pressure hot pressed TiB2 and conventionally hot pressed TiB2 were determined as a function of test temperature up to 1400C. The second phase of the program was concerned with the mechanism of densification of hafnium diboride in high pressure hot pressing. Densification studies for conventional hot pressing were reviewed and the results correlated with the hafnium diboride work. The final stage of densification was analyzed in terms of the Nabarro-Herring flow model. The principal variable studied was the fabrication temperature, although some attention was given to the fabrication time and pressure. (Author)