Instability Induced Phase Transformations in Heterogeneous AM builds
Abstract
Metal additive manufacturing (AM), also known as 3D printing, enables the production of complex engineering parts with minimal waste. However, the microstructures of printed materials are usually heterogeneous, unstable, and are prone to defect formation comparedto their traditionally processed counterparts. This is one of the reasons why adoptions of AM by various industry sectors has been limited to single-phase materials to avoid further complexity. In demanding applications such as in defence and in particular marineapplications, unique combinations of strength, ductility, and corrosion resistance are required. These advanced property profiles can only be met when designing using muti-phase alloys. Printing of such materials is challenging due to the non-equilibrium and metastable nature of the phases and the inherent microstructural topology. The current project looks at the possibility of leveraging the non-equilibrium state of as-printed multi-phase steels to engineer specialequilibrium microstructures by controlling phase fractions and their topology, also to arrive at unique mechanical and functional properties. This will be achieved through a collaborative effort between Imperial College London and researchers at Carnegie Mellon University and University of Tennessee, Knoxville in the United States. Developing large engineering parts of complex geometry using duplex metallic materials enabled via additive manufacturing methods such as wire arc additive manufacturing (WAAM) will offer improved performance and functionality for critical applications in line with the ONR research priority of creating and developing AM materials and processes for naval applications. The outcome of this fundamental research, i.e., understanding the physical metallurgy of the builds at different length scales, can be harnessedto qualify AM processed multi-phase alloys for high value-added components in naval applications. The results will be communicated through journal publications and oral presentations.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 10, 2025
- Source ID
- N629092512021
Entities
People
- N. Haghdadi
Organizations
- Imperial College London
- Office of Naval Research
- United States Navy