DOCTORAL CANDIDATE
Pranay Kumar Sivolla 

SUPERVISORS
Prof. Damien Fabregue, Institut National des Sciences Appliquées de Lyon (INSA-L)
Prof. Matthew Barnett, Deakin University (Deakin)

Metallurgy, Mechanics of Materials

High entropy alloys (HEAs) represent a novel approach to alloy design, combining nearly equal parts of multiple elements. Traditionally, alloy design has involved taking one primary element and adding small amounts of other elements. Initial research on HEAs focused on single-phase solid solution materials, but recent efforts have shifted towards utilizing hardening precipitation to achieve better mechanical strength, similar to conventional alloys like steels. This has led to the development of high entropy superalloys involving complex ordered and disordered phases.

This project aims to investigate strengthening mechanisms in medium entropy alloys (MEAs) by introducing specific alloying elements and employing heat treatments to induce precipitation hardening. The study will focus on the formation of new phases and their impact on mechanical properties, complemented by modeling precipitation kinetics using physically-based models. The objectives are to identify and select specific alloying elements for model medium entropy alloys, conduct heat treatments to promote the precipitation of new phases, characterize these phases in detail, measure their influence on mechanical properties, and model precipitation kinetics using physically-based models. A comprehensive literature review will cover the current state of research on high and medium entropy alloys, precipitation hardening mechanisms, and modeling techniques. The alloy design and preparation will involve selecting specific elements based on criteria that promote effective precipitation.

The synthesis of medium entropy alloys will follow established procedures. Heat treatments will be conducted with detailed protocols to induce precipitation, and advanced characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) will be used to analyze the newly formed phases and Mechanical testing will measure properties such as hardness, tensile strength, and ductility to assess the impact of the new phases. Physically-based models will be employed to predict precipitation kinetics, providing a theoretical framework to support experimental findings.

Expected outcomes include identifying effective alloying elements that promote precipitation hardening, a detailed understanding of the newly formed phases and their structures, enhanced mechanical properties of the medium entropy alloys, and validated models for predicting precipitation kinetics. These findings will advance the scientific understanding of high entropy alloys and their strengthening mechanisms, offering practical implications for developing new, high-performance materials for various engineering applications.