MICROSTRUCTURE OF VAPOR QUENCHED TI-29 WT-PERCENT MG ALLOY SOLID-SOLUTION

A Ti-29 wt % Mg (Ti-45 at % Mg) alloy produced by vapour quenching has been studied using scanning electron microscopy, transmission electro n microscopy, energy dispersive X-ray spectroscopy, imaging parallel e lectron energy-loss spectroscopy and electron diffraction. The alloy i s shown to be composed of highly supersaturated solid solutions betwee n two elements hitherto believed to be immiscible. It has a microstruc ture consisting of columnar units, columnar grains, columnar subgrains , herring-bone patterns and parallel stripes ranging in size from 15 m u m to 2 nm. Superimposed on the microstructure are periodic compositi onal bands with a period of similar to 0.5 mu m. The origins of the pe riodic compositional bands and the herring-bone patterns are discussed .