A TEM study of the habit plane structure of intragrainular proeutectoid α precipitates in a Ti–7.26 wt%Cr alloy

Abstract

The crystallography and the structure of the habit plane of proeutectoid α precipitates in β matrix in a Ti–7.26 wt%Cr were studied using TEM. The orientation relationship was found to deviate slightly from the ideal Burgers orientation relationship. The habit plane of precipitates was found to be normal to a particular set of Δ g ’s. A set of dislocations, about 11 nm apart, were observed on the habit plane of the precipitates. The Burgers vector of the dislocations, as determined by g · b contrast analyses, is [1 −1 1] β /2([2 −1 −1 3] α /6) . This Burgers vector is different from those determined by previous investigations. The observations are discussed in terms of an analytical O-line model and tend to support the prediction of the O-line model.