An alternative method to separate and analyse the microtextures and microstructures of primary alpha grains and transformed beta grains in near-α titanium alloy Timetal 834

An alternative technique to that recently put forward by Germain et al. [Materials Characterization 54 (2005) 216-222] to separate the orientations of primary alpha (αp) grains from those of transformed beta (αs) grains in the near-α titanium alloy Timetal 834 is presented. This new method involves correlating orientation image maps (OIM) obtained through electron back-scattered diffraction (EBSD) with optical images of the same area. By using optical microscopy and an appropriate etch, strong contrast between αp and αs is obtained enabling regions within an OIM containing the αp and αs to be determined using relatively straightforward image analysis. Results are presented for both high-resolution microstructure analysis and texture level EBSD datasets for material subjected to a simulated industrial thermomechanical forging process. A comparison is also made between the texture datasets for both αp and αs obtained using this method and that obtained using grain size distribution acquired directly from the EBSD dataset. In this case very little difference was found between the separated textures, suggesting that in the first instance a morphological/grain size approach direct from the EBSD dataset is sufficient for observing any trends in texture evolution of both αp and αs.