GOALI: Exploring advanced strategies for controlling the distribution of nanoparticles during solidification of metal matrix nanocomposites

NON-TECHNICAL SUMMARY

This research project aims to develop next-generation lightweight metals, with a focus on aluminum alloys reinforced with nanoparticles. These nanoparticles have sizes 1/1000 smaller than human hair, but when added to metals, they can strengthen metals so that less of the material is needed to provide structural integrity. Such composite materials are critical for industries like aerospace and automotive due to reduced material and energy consumption.

A key challenge in manufacturing these composites is achieving a targeted distribution of nanoparticles during the casting (solidification) process. For example, an uneven distribution of nanoparticles can lead to a weaker material. The team is investigating the interactions between the nanoparticles and the solidifying metal to understand the mechanisms that influence particle distribution.

By using state-of-the-art experimental techniques and computational models, this work is identifying the processing conditions that ensure a desirable distribution of particles. This research is expected to advance the science underlying metal processing by providing the insights needed to produce high-strength materials. This work has broader implications for the manufacture of advanced materials with tailored properties via solidification and offers insights that could be applied to other types of materials.

Additionally, the project is training future engineers in cutting edge materials science and is engaging underrepresented groups in STEM fields through outreach programs. TECHNICAL SUMMARY

The goal of this project is to address the fundamental mechanisms governing nanoparticle redistribution during solidification in metal-matrix nanocomposites (MMNCs). Specifically, the focus is on aluminum alloys reinforced with nanoscale particles. Achieving a controlled distribution of these particles is critical for realizing the desired mechanical properties such as strength, stiffness, and plasticity.

However, the kinetics of particle interaction with a moving solidification front — whether particles are pushed or engulfed — remain poorly understood due to limitations in existing models, which are often based on oversimplified assumptions. This project combines five-dimensional (3D space, time, and composition resolved), synchrotron-based x-ray imaging with phase-field simulations to explore the dynamics of particle-front interactions.

The experimental data and models will guide the development of processing strategies that control particle distribution, leading to improved MMNC microstructures, for example, by manipulating external thermal fields and the size and shape of the specimen. This work has broader implications for the manufacture of composite materials with tailored properties and offers insights that could be applied to a range of other systems, including immiscible alloys.

Additionally, the project is preparing the next generation of engineers through training in advanced experiments and simulations, while actively engaging underrepresented groups in STEM fields through outreach programs.

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.