Project Grant 2522654

COLLABORATIVE RESEARCH: DMREF: NSF-DST: METASTABILITY ENGINEERING IN REFRACTORY MULTI-PRINCIPAL ELEMENT ALLOYS -THIS DESIGNING MATERIALS TO REVOLUTIONIZE AND ENGINEER OUR FUTURE (DMREF) JOINT NSF-DEPARTMENT OF SCIENCE AND TECHNOLOGY OF INDIA (NSF-DST) PROJECT AIMS TO ESTABLISH A TRANSFORMATIVE FRAMEWORK FOR THE DEVELOPMENT OF STRUCTURAL ALLOYS THAT SIMULTANEOUSLY ACHIEVE HIGH STRENGTH AT HIGH TEMPERATURES AND ENHANCED DUCTILITY AT ROOM TEMPERATURE. THE RESEARCH FOCUSES ON A RELATIVELY NEW CLASS OF METALLIC MATERIALS KNOWN AS REFRACTORY MULTI-PRINCIPAL ELEMENT ALLOYS (RMPEAS), WHICH ARE RECOGNIZED FOR THEIR HIGH-TEMPERATURE STRENGTH BUT TYPICALLY SUFFER FROM LIMITED PLASTICITY UNDER AMBIENT CONDITIONS. THE TEAM WILL DEVELOP THE NEW ALLOY DESIGN PARADIGM THROUGH A CONCEPT CALLED ?METASTABILITY ENGINEERING,? WHICH ACTIVATES NOVEL NANO-SCALE DEFORMATION MECHANISMS BY CONTROLLING DISLOCATION DYNAMICS AND PHASE STABILITY. THE RESEARCH INTEGRATES COMBINATORIAL SYNTHESIS, ADVANCED IN-SITU EXPERIMENTS, ATOMISTIC AND MESOSCALE SIMULATIONS, AND MACHINE LEARNING (ML)-GUIDED DISCOVERY. THE RESULTING FRAMEWORK WILL ENABLE ACCELERATED DESIGN OF HIGH-PERFORMANCE RMPEAS ACROSS BROAD TEMPERATURE RANGES. IN PARALLEL, THE PROJECT WILL CONTRIBUTE TO TRAINING A NEW GENERATION OF MATERIALS SCIENTISTS IN EXPERIMENTAL, COMPUTATIONAL, AND DATA-DRIVEN METHODS, WHILE SUPPORTING OUTREACH AND INTERNATIONAL COLLABORATION THROUGH PARTNERSHIPS WITH FIVE US UNIVERSITIES AND INDIAN INSTITUTE OF TECHNOLOGY BOMBAY. THIS PROJECT AIMS TO ESTABLISH A TRANSFORMATIVE FRAMEWORK FOR METASTABILITY ENGINEERING IN REFRACTORY-TYPE MULTI-PRINCIPAL ELEMENT ALLOYS (RMPEAS) THAT COMBINES HIGH-TEMPERATURE STRENGTH WITH IMPROVED ROOM-TEMPERATURE DUCTILITY AND STRAIN HARDENABILITY. THIS PROJECT WILL ADDRESS TWO KEY TECHNICAL THRUSTS: (1) UNDERSTANDING DISLOCATION DYNAMICS FOR SOLID-SOLUTION STRENGTHENING AT BOTH ROOM AND HIGH TEMPERATURES, AND (2) ENABLING NANO-SCALE TRANSFORMATION-INDUCED PLASTICITY (NANO-TRIP) AND TWIN-INDUCED PLASTICITY (NANO-TWIP) MECHANISMS FOR ENHANCING DUCTILITY AT ROOM TEMPERATURE. TO NAVIGATE THE VAST COMPOSITION AND PROCESSING SPACE, THE TEAM WILL INTEGRATE COMBINATORIAL SYNTHESIS, HIGH-THROUGHPUT AND AUTONOMOUS MECHANICAL TESTING, AND ADVANCED MACHINE LEARNING TECHNIQUES TO ACCELERATE THE DISCOVERY OF HIGH PERFORMANCE RMPEAS. IN THE FIRST THRUST, THE PROJECT WILL QUANTIFY THE CONTRIBUTIONS OF DISLOCATIONS TO HIGH-TEMPERATURE STRENGTH THROUGH AUTONOMOUS NANOINDENTATION CREEP TESTING, IN SITU NEUTRON DIFFRACTION, AND ATOMISTIC SIMULATIONS. ADVANCED MICROSCOPY TECHNIQUES WILL BE USED TO REVEAL HOW LOCAL CHEMICAL ORDERING AND LATTICE DISTORTION AFFECT DISLOCATION MOTION. IN THE SECOND THRUST, THE TEAM WILL IDENTIFY COMPOSITION-PROCESSING PATHWAYS THAT PROMOTE METASTABLE DEFORMATION MODES USING THERMODYNAMIC MODELING, COMBINATORIAL DEPOSITION, AND TRANSFORMER-BASED MACHINE LEARNING MODELS. THESE MODELS WILL PREDICT TWIP/TRIP PROPENSITY AND GUIDE MULTI-OBJECTIVE OPTIMIZATION ACROSS LARGE ALLOY DESIGN SPACES. DOWN-SELECTED ALLOY SYSTEMS WILL BE VALIDATED THROUGH MULTISCALE MECHANICAL TESTING AND SIMULATIONS THAT SPAN ATOMIC TO BULK SCALES. COLLECTIVELY, THE PROJECT WILL DELIVER A MECHANISTIC FOUNDATION AND DATA-DRIVEN DESIGN TOOLS FOR METASTABILITY ENGINEERING IN RMPEAS, ALIGNING WITH THE DMREF PROJECT?S MISSION TO ACCELERATE MATERIALS INNOVATION THROUGH THE INTEGRATION OF THEORY, EXPERIMENTATION, AND DATA SCIENCE WITH CLOSED-LOOP DESIGN CYCLES. THIS AWARD REFLECTS NSF'S STATUTORY MISSION AND HAS BEEN DEEMED WORTHY OF SUPPORT THROUGH EVALUATION USING THE FOUNDATION'S INTELLECTUAL MERIT AND BROADER IMPACTS REVIEW CRITERIA.- SUBAWARDS ARE NOT PLANNED FOR THIS AWARD.