Fundamental Studies of Beta Phase Decomposition Modes in Titanium Alloys.

摘要

Extensive efforts were made during this grant year to prepare generic overviews on major aspects of phase transformations. Topics on which overviews have been completed or are presently in progress as part of this activity include: crystallographic and mechanistic aspects of growth by shear vs. diffusional growth, interphase boundary structures formed during diffusional transformations in Ti-base alloys, a current summary of the technical bases for three different views of what constitutes bainite, a summary of the diffusionist views on the bainite reactions, the role of ledges in vapor-crystal, liquid-crystals and crystal-crystal phase transformations, a critique of Mats Hillerts' approach to the growth kinetics of diffusional transformations, and assessments of published studies on homogeneous nucleation kinetics in binary metallic alloys and atomic mechanism of diffusional nucleation and growth. (js)