Interface characteristics in an {\alpha}+{\beta} titanium alloy

TL;DR

This study examines the alpha/beta interface in a titanium alloy, revealing how deformation affects interface structure and providing insights for improving processing techniques.

Contribution

It offers detailed analysis of interface characteristics before and after cold work, linking deformation to interface modifications in Ti-6Al-2Sn-4Zr-6Mo.

Findings

Semi-coherent interface steps match theoretical predictions.

Deformation causes larger, less coherent steps and dislocation pile-up.

Insights into interface behavior aid titanium alloy processing design.

Abstract

The alpha/beta interface in Ti-6Al-2Sn-4Zr-6Mo (Ti-6246) is investigated via centre of symmetry analysis, both as-grown and after 10% cold work. Semi-coherent interface steps are observed at a spacing of 4.5 +/-1.13 atoms in the as-grown condition, in good agreement with theory prediction (4.37 atoms). Lattice accommodation is observed, with elongation along [-1 2 -1 0]alpha and contraction along [1 0 -1 0]alpha . Deformed alpha exhibited larger, less coherent steps with slip bands lying in {110}beta. This indicates dislocation pile-up at the grain boundary, a precursor to globularisation, offering insight into the effect of deformation processing on the interface, which is important for titanium alloy processing route design.