材料期刊网

Ti-47Al-2W-0.5Si-0.5B alloy was investigated by TEM and HRTEM. When the incident electron beam is along [0001] direction of the alpha(2) phase, there are lath-like beta phases observed. beta precipitates exhibit six different lath directions. The long axis growth directions of beta phases are all about 14degrees away from the close-packed directions of the two phases. The orientation relationship (OR) between the beta and alpha(2) phases is (0001)(alpha2)//{110}(beta), [11(2) over bar0](alpha2)//[111](beta). The lath growth directions of phases are predicted from the invariant line strain model. (C) 2003 Elsevier Science B.V. All rights reserved.