Advances in Titanium Technology: Session II
Sponsored by: TMS Structural Materials Division, TMS: Titanium Committee
Program Organizers: Yufeng Zheng, University of North Texas; Zachary Kloenne, Ohio State University; Fan Sun, Cnrs Umr 8247 - Chimie Paristech Psl; Stoichko Antonov, National Energy Technology Laboratory; Rongpei Shi, Harbin Institute of Technology (Shenzhen)
Monday 2:00 PM
March 20, 2023
Room: Cobalt 500
Location: Hilton
Session Chair: Fan Sun, CNRS - PSL Research University
2:00 PM Invited
Design of Compositionally Modulated Ti-Alloys for Novel Microstructures and Exceptional Properties: Yunzhi Wang1; 1Ohio State University
In this presentation, we review different approaches (including spinodal decomposition, dissolution of precipitates, annealing of multilayers, and additive manufacturing) to creating concentration modulations (CMs) for the design of novel microstructures with unprecedented properties. We demonstrate how the CMs produced at different length scales (from nanometers to microns) allow for engineering heterogeneous and hierarchical dual-phase microstructures by enabling different transformation mechanisms. These heterogeneous and hierarchical microstructures have the ability to regulate strain release during deformations by activating different deformation mechanisms at different stages, and offer unprecedented mechanical properties including linear superelasticity, ultralow elastic modulus, exceptional combination of high strength, high work-hardenability, and high ductility. This presentation demonstrates a new paradigm of heterogeneous alloy design utilizing CMs for structural and functional applications.
2:30 PM Invited
The Effects of Fe and Al Additions on the Microstructure and Mechanical Property Evolution of Ti-11at.%Cr Alloys: JoAnn Ballor1; Ashiq Shawon1; Alex Zevalkink1; Scott Misture2; Jonathan Poplawsky3; Carl Boehlert1; 1Michigan State University; 2Alfred University; 3Oak Ridge National Laboratory
Low-cost alloying elements can help lower the cost of beta-titanium (Ti) alloys, and alloy composition is important for developing desired microstructures during processing. The low-cost alloying elements iron (Fe) and aluminum (Al) were added to a base Ti-11at%chromium (Cr) alloy, and an in-situ investigation of the mechanical properties and microstructural evaluation during 400C exposures was conducted. X-ray diffraction revealed that Ti-Cr and Ti-Cr-Fe alloys underwent the beta-to-omega and beta-to-alpha transformations, where the 0.85at% Fe addition reduced the volume fraction of the omega phase. The addition of 5.3at% Al (for the TCA and TCFA alloys) inhibited the beta-to-omega transformation. Resonance ultrasound spectroscopy indicated that the alloys containing the omega phase exhibited an increase in shear modulus of approximately 140%, while the alloys which exhibited only the beta-to alpha phase transformation exhibited an increase of approximately 102%. The kinetics of the phase transformations, which influenced the mechanical properties, will be illustrated.
3:00 PM
In-situ Observation of Twinning Pathways in TRIP/TWIP Ti-12Mo Alloy: Fan Sun1; Bingnan Qian2; Lola Lilensten1; Philippe Vermaut1; Frédéric Prima1; 1CNRS - PSL Research University; 2Southern University of Science and Technology
The metastable beta Ti-12Mo alloy exhibits both TRansformation Induced Plasticity (TRIP) and TWinning Induced Plasticity (TWIP) during tensile deformation. TRIP is due to martensitic transformation induced by plastic deformation. TWIP is resulted from mechanical twinning in not only beta phase (BCC phase) but also stress-induced martensite. The shear strains of these twinning operations contribute to the plasticity of the alloy. The presentation will introduce the recent results about the complex twinning pathways observed in the alloy, focusing on the special twinning-detwinning process in martensite. The experiments are carried out using in-situ EBSD and TEM characterizations. The results show that two twinning modes {130}<-310> and {110}<-110> are operational in the martensite. The hierarchical twinning is observed in the martensite leading to complex twin structure. During tensile unloading, a multi-step detwinning process reverses the twinned martensite to its original orientation, resulting in rubber-like mechanical behavior.
3:20 PM Break
3:40 PM
High Strain Rate Deformation in Metastable β-Titanium Alloys: A Case Study of Ti-1023: Abhishek Sharma1; Mohan Sai Kiran Nartu1; Ravisankar Haridas1; Sriswaroop Dasari1; Srinivas Aditya Mantri1; Jeffrey T Lloyd2; Rajarshi Banerjee1; 1University of North Texas; 2DEVCOM Army Research Laboratory
While metastable β-Titanium alloys are commercially used for many structural applications, their suitability for ballistic applications has not been well explored. This presentation investigates the ballistic properties of metastable β-Titanium alloys, specifically focusing on the high-strain rate performance of Ti-10V-2Fe-3Al (wt.%), commonly known as Ti-1023. Employing combinations of cold-rolling and sub-β-solvus heat treatments, the distribution of α, αʹʹ and ω-phases within a β matrix has been tailored, and their influence on the strength and strain-hardenability during high-strain rate compression testing has been investigated. Varying the degree of cold rolling permits the exploitation of a wide window of macroscopic mechanical properties in these alloys. Detailed post-deformation microstructural analysis revealed the microscopic mechanisms at such high strain rates. A combination of transformation induced plasticity (TRIP) and internal twinning within the resultant martensite laths along with lath-lath interactions appear to provide a good balance of strength and strain hardenability in these alloys.
4:00 PM
Stress Induced Martensitic Transformation and Twinning in Beta Titanium Alloys with Increased Oxygen Content: Mariano Casas Luna1; Jiří Kozlík1; Dalibor Preisler1; Hanuš Seiner1; Tomáš Chráska1; Josef Strasky1; 1Charles University
Various Ti-Nb-Zr-O based biomedical alloys were prepared from elemental powders and titanium dioxide powder by Field Assisted Sintering Technique (FAST). Four layered samples covering together 24 chemical compositions were prepared. Selected chemical compositions were prepared also by a common arc melting. Compression tests were performed at room temperature, and the deformed microstructures were analyzed by electron back-scatter diffraction (EBSD). Both stress induced martensite and {332}<113> twinning was found, strongly depending on a particular Nb content. Sequence of formation of martensitic phase / twins during cooling and deformation was derived form a detail analysis of EBSD data (Kikuchi patterns). Effect of Nb and O on stability of parent beta matrix was estimated.