A critical review of experimental results and constitutive descriptions for metals and alloys in hot working

Materials discovery and design using machine learning

Recent advances in the development of aerospace materials

Machine learning strategies for systems with invariance properties

Surface modification of titanium and titanium alloys: Technologies, developments, and future interests

Ageing response of a Al–Cu–Li 2198 alloy

Isothermal compressions of near-alpha Ti60 alloy were carried out on a Gleeble-3800 simulator in the temperature range of 960-1110 degrees C and strain rate range of 0.001-10.0 s(-1). The high-temperature deformation behavior was characterized based on an analysis of the stress-strain behavior, kinetics and processing map. The flow stress behavior revealed greater flow softening in the two-phase field compared with that of single-phase field. In two-phase field, flow softening was caused by break-up and globularization of lamellar a as well as deformation heating during deformation. While in the single-phase field, flow softening was caused by dynamic recovery and recrystallization. Using hyperbolic-sine relationships for the flow stress data, the apparent activation energy was determined to be 653 kJ/mol and 183 kJ/mol for two-phase field and single-phase field, respectively. The processing map exhibited two instability fields: 960-980 degrees C at 0.3-10 s(-1) and 990-1110 degrees C at 0.58-10 s(-1). These fields should be avoided due to the flow localization during the deformation of Ti60 alloy. (C) 2011 Elsevier B.V. All rights reserved.

High-temperature deformation behavior of Ti60 titanium alloy

The hot deformation behavior of as-cast TC21 titanium alloy has been investigated in the isothermal compression of the alloy using processing maps conducted at the deformation temperature ranging from 1000 °C to 1150 °C, the strain rate ranging from 0.01 to 10 s−1, and the height reduction of 60%. The constitutive equation of as-cast TC21 alloy is developed in the form of the exponential law and the deformation activation energy is calculated to be about 185.51 kJ/mol. Based on the dynamic materials model and Prasad's instability criterion, the processing maps of as-cast TC21 titanium alloy are constructed at strains of 0.4 and 0.6. Deformation mechanisms in the stable and unstable regions are verified through the microstructure observation. The maps exhibit a stable domain with the temperature range of 1000–1150 °C and strain rate range of 0.01–0.1 s−1 with two peak efficiencies of power dissipation, one is 48% occurring at 1000 °C/0.01 s−1 that is associated with dynamic recovery, the other is 38% occurring at 1150 °C/0.01 s−1, which displays the feature of continuous recrystallization. Therefore, the optimal processing condition of the alloy is 1150 °C/0.01 s−1. In addition, the material undergoes flow localization at strain rates higher than 1 s−1 which has to be avoided in hot processing for obtaining satisfactory properties. Thus the applicable cogging temperatures and cogging strain rates for as-cast TC21 alloy are 1000–1150 °C and 0.01–0.5 s−1, respectively.

Characterization of hot deformation behavior of as-cast TC21 titanium alloy using processing map

Effect of microstructure on tensile properties of Ti–5Al–5Mo–5V–3Cr–1Zr alloy

Comparative study on constitutive relationship of as-cast Ti60 titanium alloy during hot deformation based on Arrhenius-type and artificial neural network models

Weidong Zeng

Papers

Ageing response of a Al–Cu–Li 2198 alloy

High-temperature deformation behavior of Ti60 titanium alloy

Characterization of hot deformation behavior of as-cast TC21 titanium alloy using processing map

Effect of microstructure on tensile properties of Ti–5Al–5Mo–5V–3Cr–1Zr alloy

Comparative study on constitutive relationship of as-cast Ti60 titanium alloy during hot deformation based on Arrhenius-type and artificial neural network models