IMPLICATIONS OF A PRESSURE-INDUCED PHASE-TRANSITION IN THE SEARCH FORCUBIC TI3AL

High-pressure x-ray diffraction studies of the high temperature struct ural intermetallic, Ti3Al (DO19 structure at NTP), were carried out wi th the motivation of finding clues for identifying the alloying elemen ts for stabilizing the cubic L1(2) structure, which is expected to hav e better ductility. The present investigation revealed a structural tr ansition from DO19 to DO24 structure in the pressure range 10-15 GPa. The geometrical relationship between these two structures and the poss ible mechanism of the transition have been elucidated. From this inves tigation follow two important results that may have significant bearin g in the search for the cubic Ti3Al.