On the texture formation of selective laser melted Ti-6Al-4V

Selective laser melting (SLM) has been shown to be an attractive manufacturing route for the production of α/β titanium alloys. The relationship between the SLM process parameters and the microstructure of titanium alloys has been the object of several works, but the texture formation during the SLM process has yet to be understood. In the present study, the texture formation of Ti-6Al-4V components was investigated in order to clarify which microstructural features can be tailored during the SLM process. The microstructural characterization of the as-built components was carried out using various microscopy techniques. Phase and texture analysis were carried out using backscattered electron imaging and diffraction. It was found that as-built components consist exclusively of α’ martensitic phase precipitated from prior β columnar grains. The texture of the prior β phase was reconstructed and discussed in relation to the used SLM process parameters. It was found that the β grain solidification is influenced by the laser scan strategy and that the β phase has a strong texture along its grain growth direction. The α’ martensitic laths that originate from the parent b grains precipitate according to the Burgers orientation relationship. It was observed that α’ laths clusters from the same β grain have a specific misorientation that minimizes the local shape strain. Texture inheritance across successive deposited layers was also observed and discussed in relation to various variant selection mechanism

Data Driven Tools and Methods for Microtexture Classification and Dwell Fatigue Life Prediction in Dual Phase Titanium Alloys

Microtexture has been linked to large reductions in cold dwell fatigue (CDF) life of specific dual phase titanium alloy aeroengine components. A recently completed Metals Affordability Initiative (MAI) funded program led by Pratt & Whitney (P&W) and includes ATI Forged Products, Boeing, GE Aviation, Rolls Royce (RR), Arconic, Titanium Metals Corporation (TIMET), PCC-Wyman Gordon (PCC-WG), Scientific Forming Technologies (SFTC), Materials Resources LLC (MRL) and The Ohio State University (OSU) has developed improved techniques for the characterization of microtexured regions (MTR) in titanium billet and forgings, and integrated computational materials engineering (ICME). These methods are aimed at developing and integrating process and property modeling tools for the prediction of microtexture and fatigue life in titanium components. These characterization and fatigue life prediction tools have near-term application off ramps that will enable use for process and product development and quality control. Key results for two widely used alloys, Ti-6242 and Ti-64, will be reviewed in this paper

Data Driven Tools and Methods for Microtexture Classification and Dwell Fatigue Life Prediction in Dual Phase Titanium Alloys

Microtexture has been linked to large reductions in cold dwell fatigue (CDF) life of specific dual phase titanium alloy aeroengine components. A recently completed Metals Affordability Initiative (MAI) funded program led by Pratt & Whitney (P&W) and includes ATI Forged Products, Boeing, GE Aviation, Rolls Royce (RR), Arconic, Titanium Metals Corporation (TIMET), PCC-Wyman Gordon (PCC-WG), Scientific Forming Technologies (SFTC), Materials Resources LLC (MRL) and The Ohio State University (OSU) has developed improved techniques for the characterization of microtexured regions (MTR) in titanium billet and forgings, and integrated computational materials engineering (ICME). These methods are aimed at developing and integrating process and property modeling tools for the prediction of microtexture and fatigue life in titanium components. These characterization and fatigue life prediction tools have near-term application off ramps that will enable use for process and product development and quality control. Key results for two widely used alloys, Ti-6242 and Ti-64, will be reviewed in this paper

Orientation effect on mechanical properties of commercially pure titanium at room temperature

The effect of sample orientation on the mechanical properties of commercially pure (CP) titanium plate with a transverse split basal texture was investigated at room temperature (RT) using plane strain compression (PSC). A large variation in flow stress of up to (EBSD) and calculating Schmid factors for all important slip and twinning modes. Importantly, the Schmid factors were calculated for all orientations in Euler space because there are significant variations over all orientations for the PSC stress state, unlike uniaxial compression or tension. The Schmid factor analysis and twin data for the wide variety of orientations tested enabled the conclusion to be drawn reliably that higher flow stresses were primarily due to an unfavourable orientation for prism- slip. A greater proportion of to twinning was also a major factor in the higher flow stresses. Increased strain hardening was observed in the sample orientation that showed a dramatic texture change to a more difficult orientation for further deformation as a result of dominant twinning. This indicated that reorientation hardening was the responsible mechanism