CHARACTERIZATION OF UNUSUAL STACKING-FAULTS AND DISLOCATIONS IN THE MASSIVE GAMMA(M)-PHASE IN A QUENCHED TI-46 AT-PERCENT AL

Transmission electron microscopy was used to characterize stacking fau lts and dislocations observed in the massive gamma (gamma(m)) phase fo rmed in a Ti-46 at% Al alloy quenched from the alpha-phase field. The results reveal that 1/2[101] unit dislocations and stacking faults bou nd by 1/6[121] Shockley partial of all possible types, were present in the gamma(m) phase. In addition, antiphase boundaries were found to c ommence or terminate on the 1/2[101] unit dislocations and on the stac king faults at the partial dislocations with b = 1/6[121], but not tho se with b = 1/6[112]. These results are presented and discussed. (C) 1 998 Elsevier Science B.V. All rights reserved.