Hot Deformation Behavior and Microstructure Evolution of a New Near β Titanium Alloy Reinforced with Trace TiCp. Issue 2 (10th October 2018) - Zhang, Changjiang
Abstract : In this study, hot deformation behavior and microstructure evolution of a new near beta titanium alloy reinforced with trace TiCp (2 vol%) are investigated by isothermal compression test. The flow stress curves present various characteristics based on the deformation parameters. The hot deformation activation energy is determined to be 507.1 KJ mol −1, which is lower than that of the matrix alloy. Based on the dynamic material model (DMM), processing map at the strain of 0.6 indicates that flow instability mainly concentrates at 780–820 °C and strain rate higher than 0.22 s −1 . Results of microstructure evolution illustrate that flow instability is characterized by the cracking, localized plastic flow, and bending of TiC particles. In the safety region, the morphology and fraction of α and β phases are closely depended on deformation conditions. At α / β field, dynamic recrystallization (DRX) of β grains dominants the deformation mechanism due to the existence of TiC particles by providing nucleation sites. Meanwhile, the DRX degree of β grains is enhanced markedly compared with that of the matrix alloy in β phase field. Finally, deformation mechanism evolution under the given processing conditions is illuminated. Abstract : The hot deformation mechanism of a new near beta titanium alloy reinforced with trace TiCp (2 vol%) is investigated through isothermal compression test. The flow stress curves for current materials are discussed. The processing map and typical deformed microstructure are presented. And deformation mechanism evolution is presented through the schematic diagram.