EAGER: Controllable Synthesis of Gradient-Microstructured Materials, from the Nanoscale to Macroscale

University Of California-Riverside, Riverside CA

Investigators

Abstract

Gradient-structured materials are materials which have nanometer sized structure at the surface, and coarser structure at the core. Such materials have demonstrated impressive mechanical performance advantages over materials with homogeneous coarse-grained or nanocrystalline structures. So far, however, the ability to manufacture gradient structured materials for commercial use has not yet been realized. This award supports research to develop deeper scientific understanding of processing parameters that control the microstructures in both thin film and bulk materials, and in particular this EArly-concept Grant for Exploratory Research (EAGER) award will support demonstration of the fabrication and synthesis of these novel gradient structures. The ability to fabricate these structures will allow for scientific investigation of their behavior, and the new knowledge gained from this research will enable the design of engineered materials with improved resistance to wear and corrosion, and also drastically improved yield strength and toughness. The benefits of this work will manifest in improved performance and product lifetimes for components subjected to extreme engineering environments in automotive, aerospace and machine tools industries. The research objective of this early-stage work is to explore novel processing approaches for obtaining materials with controllable grain size gradients. To realize the goal of controllable grain size gradients in both thin-film and bulk samples, a systematic investigation of two processing approaches will be carried out, with the specific goal of understanding how processing parameters can be correlated with gradient microstructural evolution. These tasks include sputtering fabrication of gradient titanium thin-films with tailored layer thicknesses, grain size gradients, and graded-interfaces, and surface mechanical attrition treatment of titanium informed by numerical models of microstructural refinement. The scientific insights stemming from this research will provide a clearer picture on the effect of processing conditions on the microstructural evolution of gradient microstructure materials, and facilitate a better understanding of the property space available for gradient nanostructured materials, which may accelerate insertion into future structural and coating applications.