Current Projects

“The thermodynamic punishment must fit the structural crime.”

CAREER: Computer-Assisted Experimental Phase Equilibria (CAEPE)

Source of Support:  National Science Foundation (NSF)
Duration: 07/01/2021 to 06/30/2026 
PI: Scott J. McCormack

Aim/Abstract: The computer-assisted experimental phase equilibria (CAEPE) methodology will be established to determine quaternary and quinary ceramic phase diagrams precisely and efficiently in a timely manner. This new integrated computational materials engineering (ICME) methodology will lead to a paradigm shift in the way multi-component phase equilibria will be collected. It will be performed in conjunction with high temperature experiments: (i) In-situ high temperature X-ray diffraction using a environmentally controlled conical nozzle levitator system equipped with dual lasers (CO2 and fiber laser) along with (ii) high temperature solution calorimetry will be used to rapidly elucidate the ZrC-NbC-HfC-TaC-TiC pseudo-quinary phase diagram. This work will answer critical questions in high entropy materials such as: (i) How do multiple components affect the melting point (liquidus)? (ii) At what temperatures are these systems entropy stabilized (miscibility gaps)? and (iii) do multiple components de-stabilize ordered structures (order-disorder transitions)?

Uncertainty quantification and processing optimization for UHTC manufacturing through an ICME framework                

Source of Support:  Air Force Office of Scientific Research (AFOSR)
Duration: 02/01/2022 to 01/31/2025  
PI: Scott J. McCormack
Co-PI: William Fahrenholtz (Missouri S&T)
Co-PI: Wei Xiong (UPitt)
Co-PI: Hessam Babaee (UPitt)

Aim/Abstract: Standard ultra-high temperature ceramic (UHTC) manufacturing creates components with large differences in properties due to variability in microstructural “critical flaw” distributions. Critical flaws can be any irregularity in a component, such as a secondary phase, inclusion, crack, pore etc. This is problematic when designing reproducible UHTC components for Mach 6 hypersonic applications. The goal of this project is to build probabilistic characterization of processing-structure-properties (PSP) parameters and link them at each stage of UHTC processing in a way that allows for uncertainty propagation. This methodology has not been performed in the past due to the complex interrelations of UHTC PSP parameters that need to be deconvoluted. Thus, multi-fidelity PSP database development and effective integrated computational materials engineering (ICME) combined with statistical modeling is key to minimize uncertainty during UHTC manufacturing. This approach will consist of three key integrated thrusts: Thrust I: Manufacturing and rapid materials characterization: to populate a multi-fidelity PSP database using a combination of lower-fidelity in-lab experiments and modeling along with higher-fidelity synchrotron 3-D microstructural characterization experiments. Thrust II: Uncertainty quantification: to develop a PSP-ICME database in tandem with multi-fidelity statistical modeling using a Bayesian neural network approach. Thrust III: Validation of the multi-fidelity model: to verify that the statistical model can reduce uncertainty in UHTC manufacturing in terms of properties and microstructural flaws. The densification of ZrB2 will be used as a model system for this methodology as it is a prime candidate for ceramic matrix materials in hypersonic- ready ceramic matrix composites (CMCs). This work will be completed in collaboration with Air Force Research Laboratory (AFRL) in Dayton, Ohio with the goal of establishing expertise pipelines via training students in UHTC manufacturing, multi- fidelity materials characterization and modeling, and uncertainty quantification.

Liquidus mapping of actinide alloys

Source of Support:  Lawrence Livermore National Security (LLNS)
Duration: 10/01/2023 to 09/30/2025
PI: Scott J. McCormack

Aim/Abstract: First principles ab-initio techniques such as density functional theory (DFT) struggle to reliably predict properties of actinide materials due to the 5f electrons and to accurately calculate high-high temperature properties of materials due to inherent anharmonic effects. These two compications compound when trying to understand the high-temperature properties of actinide materials. This makes it extremely difficult to develop predictive models for applications related to actinide alloy processing (e.g., casting) and next-generation nuclear fuels in high-temperature operations. This proposed work aims to circumvent these issues by measuring the high-temperature properties of U-Nb-Ti, specifically their melting point, using a radioactive material chamber conical nozzle levitation system (RAD-CNL) equipped with laser heating (400 W CO2 and 500 W Yb lasers). 

Ultra high temperature material synthesis and degradation mechanisms in hypersonic flight

Source of Support:  UC-National Lab In-Residence Graduate Fellowship (LFRP)
Duration: 04/01/2023 to 07/01/2025 
Fellowship Awardee: William Rosenberg
Fellowship Mentor: Scott J. McCormack

Aim/Abstract: To synthesize, characterize, and experimentally investigate the degradation mechanisms of ultra-high temperature carbides and carbonitrides in-situ under simulated hypersonic flight conditions. This will be achieved through leveraging: (i) the high temperature (1800 ̊C) controlled atmosphere (H2, CH4, N2, Ar) reactor (HT-CAR) system equipped with glovebox and residual gas analyzer to synthesize stoichiometrically precise carbides and carbonitrides in oxygen free environments, (ii) the dual laser, environment-controlled conical nozzle levitator (E- CNL) system to achieve temperatures of up to ~4000 ̊C (ii) Energy Matter Interaction Tunnel (EMIT), a material testing hypersonic wind tunnel designed to reach up to Mach 5 at ablation temperatures, with in-situ monitoring capabilities. Ultra-high temperature ceramic (UHTC) experimental leading edge materials such as Hafnium Carbide (HfC) and Tantalum Carbide (TaC), along with the highest experimentally known melting point compound, (Hf.8Ta.2)C (Tmelt. = ~3942 ̊C), and the highest calculated melting point compound, Hf.53C.27N.20 (Tmelt. = ~4142 ̊C), will be synthesized, characterized, and studied as candidates for hypersonic leading-edge materials.

Articles that inspire our work

1. Materials Research for Fusion (2016)

2. Space Nuclear Propulsion for Human Mars Exploration (2021)

3. US hypersonic initiatives require accelerated efforts of the materials research community (2021)