Neutron diffraction to investigate thermal Stability of Ni-Based Alloys at Cryogenic and Elevated Temperatures

The project examines the high and cryogenic temperature structural response and thermal stability of a thermally sprayed nickel-based high entropy alloy (HEA) coating using advanced neutron diffraction. HEAs, comprising multiple principal elements in near-equiatomic ratios, are a novel class of materials with excellent mechanical and thermal properties. Despite increasing interest in their use as high-performance coatings, their behaviour under extreme conditions, particularly when thermally sprayed, remains poorly understood. This study focuses on a HEA, designed using machine learning and deposited via atmospheric plasma spraying at LSBU. Neutron diffraction lies at the core of the investigation, offering through-thickness insights with resolution and penetration depth not achievable by other techniques. Its ability to probe dense metallic coatings makes it ideal for assessing structural evolution under thermal loading. Comparative analysis of powder and two coated samples, supported by molecular dynamics simulations, will enhance understanding of the material’s performance in service conditions. By addressing key knowledge gaps in complex multi-element systems under non-equilibrium conditions, the project supports the development of more robust coatings for demanding applications. It aligns with UK priorities in digital manufacturing and advanced materials and forms a major part of a PhD thesis focused on intelligent thermal spray systems with embedded sensing.