Advanced Manufacturing with Real-Time Composition and Microstructure Control for Nuclear Applications

Advanced and additive manufacturing (AM) can enable materials with enhanced performance and facilitate rapid development cycles for critical nuclear components, which are subject to high thermal flux, intense irradiation fields, and high stresses. This project will demonstrate feasibility of a real-time in-situ thermal and microstructural control deposition system relevant to high performance nuclear energy alloys. A major focus of this work is to control the composition, microstructure, and mechanical properties of as-printed components. Phase I R&D tasks will involve detailed process testing of a dual-wire deposition head with integrated secondary heat source for graded composition wire-arc AM (WAAM) systems. Baseline and integrated AM thermal processing graded austenitic stainless to ferritic-martensitic steel specimens will undergo mechanical testing and advanced characterization. Feasibility studies will determine suitability of implementation on various AM processes, multimaterial volumes, and component geometries. Outreach efforts are planned with the nuclear materials and AM communities for validation, and to establish prototyping, irradiation and development partnerships, along with creating a detailed plan for Phase II demonstrations on an expanded list of nuclear-relevant transitional materials and large-scale geometries. Commercial Applications and Other Benefits: integrated processing holds potential for expanded process capability, as many candidate high performance AM materials experience cracking and/or residual stresses limiting functional use. Additionally, in-situ thermal processing could offer a pathway to large and complex multimaterial components, circumventing the need for post-build thermal processing which can be costly, distortion-inducing, time and energy consuming, or simply not feasible.