PHASE RELATIONSHIPS IN HIGH TEMPERATURE CERAMICS

PHASE BEHAVIOR STUDIES OF THE HFO(2)/TA(2)O(5) AND HFC/TAC SYSTEMS ARE PROPOSED. THIS WORK EMPHASIZES MEASUREMENT OF LIQUIDOUS TEMPERATURES AND WILL IDENTIFY PHASES PRESENT BETWEEN ABOUT 1500 DEG C AND 2500 DEG C. THE PROPOSAL INCLUDES NOVEL IN SITU METHODS INVOLVING CO(2) LASER HEATING AND THE USE OF ANNEAL QUENCH METHODS. A DIFFUSION COUPLE APPROACH IS PROPOSED AS THE MOST EFFICIENT MEANS OF EVALUATING PHASE FORMATION THROUGH USE OF ELECTRON MICROSCOPY (WITH X-RAY MICROANALYSIS CAPABILITIES) AND X-RAY DIFFRACTION METHODS. THE EFFECT OF COMBUSTION GASES ON PHASE BEHAVIOR WILL BE AN IMPORTANT RESULT OF THE STUDY.