Research Projects

The Ti-6Al-4V alloy undergoes secondary TMP, which converts its (α+β)-lamellar microstructure into a bimodal one. This process, known as spheroidization, leads to the formation of micro-textured regions (MTR) in the room temperature microstructure of the alloy. MTRs are larger than equiaxed αp-grains and play a significant role in fatigue crack initiation in components made by secondary TMP of (α+β)-Titanium alloys. During dwell in high-cycle or low-cycle fatigue, cracks usually originate from MTR sites. Field failure reports have linked MTRs to dwell fatigue of Titanium alloy engine components in aviation industries. The present proposal aims to understand MTR formation in two-phase Ti-6Al-4V alloy under industrially relevant secondary TMP operations. This knowledge will provide novel insights on the interrelation between 'orientation dependent spheroidization' and the microstructure and texture evolution during secondary TMP. This information will be used to design an efficient secondary TMP schedule to reduce MTR formation within the wrought Ti-6Al-4V alloy or produce suitable randomized texture to avoid cracking under fatigue loading in the presence of MTR. Currently, secondary TMP schedule optimization is carried out using a simple trial and error method due to limited understanding about MTR formation. This deficiency increases the cost of finished parts, especially for the aviation industry, and contributes to materials waste and environmental impacts. The proposal aims to develop Ti-6Al-4V alloy for fracture-critical applications, such as aero-engine components, and create a comprehensive knowledgebase about microstructure-processing correlation in terms of MTR formation for two-phase Titanium alloy.