Microstructural and microtextural analysis of InterPulse GTCAW welds in Cp-Ti and Ti–6Al–4V

The InterPulse   technique is an advanced gas tungsten constricted arc welding (GTCAW) method for controlled heat input welding of titanium alloys. Microstructural and microtextural analysis has been used to show that the technique has the potential to produce high integrity welds in Cp-Ti and Ti–6Al–4V while welding outside of a vacuum chamber and without a trailing gas shield. The arc waveform control provided by the technique is shown to have the potential to tailor weld macrostructures, microstructures and microtextures. At the cooling rates associated with the technique, α-variants sharing a common (1 1 2¯ 0) pole are found to cluster together into groups within prior β grains, leading to large areas where all variants are separated by a misorientation of 60°. Characterisation of these microtextures may provide new insight into microtexture–properties relations and the mechanisms of microtextural evolution.

Research highlights▶ Evaluation of a new low heat input welding technique for titanium alloys. ▶ Demonstration of the potential to tailor weld microstructures and microtextures. ▶ New insight into the mechanisms of microtextural evolution in titanium alloys. ▶ α Variants sharing a common 1 1 2¯ 0 pole are found to cluster into groups. ▶ Direct analysis of the impact of microtexture on mechanical properties.