|About this Abstract
||MS&T23: Materials Science & Technology
||Computational Discovery, Understanding, and Design of Multi-principal Element Materials
||Microstructural Engineering via Heat Treatments in Multi-principal Element Alloy Systems with Miscibility Gaps
||Shalini Roy Koneru, Kamal Kadirvel, Zachary Kleonne, Hamish Fraser, Yunzhi Wang
|On-Site Speaker (Planned)
||Shalini Roy Koneru
The occurrence of multi-phase microstructures in multi-principal element alloys (MPEAs) highlights the significant role of enthalpic contributions in phase equilibria. For instance, recent studies suggest that the experimentally observed multi-phase microstructural evolution in AlMo0.5NbTa0.5TiZr, Al0.5NbTa0.8Ti1.5V0.2Zr, TiZrNbTa, AlCoCrFeNi and Fe15Co15Ni20Mn20Cu30 can be attributed to their miscibility gaps. Thus, through high-throughput CALPHAD calculations and phase-field simulations, we investigate systematically how different heat treatment schedules such as single-step isothermal aging, two-step isothermal aging and continuous cooling could alter microstructural evolution in systems undergoing spinodal-mediated phase transformations. Our results show that continuous cooling could invert the microstructural topology (i.e., which phase forms the continuous matrix and which phase forms discrete precipitates) in the same MPEA having an asymmetric miscibility gap, while two-step isothermal aging can produce a rich variety of novel hierarchical and graded microstructures. These findings suggest that it is possible to engineer novel microstructures in MPEAs with tailored properties.