Near Net Shape Consolidation of Oxide Dispersion Strengthened Alloy Powders

Fabrication of ODS alloy structures is problematic due to 1) the inability to utilize any liquid- phase process such as casting, welding, laser cladding, etc. 2) grain coarsening caused by traditional heat treatment processes, 3) lack of geometric flexibility with current solid-state fabrication methods such as extrusion, 4) the need for coating and joining of dissimilar metals in the solid phase. Traditional thermal processing increases grain size dramatically which both reduces creep strength as well as decreases radiation resistance. Aeroprobe proposes a solid-phase, near net shape consolidation process, friction stir-fabrication (FSF), for ODS alloys and structures that will overcome these current challenges. During FSF, powder ODS precursors are simultaneously deposited and consolidated using plastic deformation. This solid-phase process prevents grain coarsening and results in a wrought metal microstructure. Robust coatings can be deposited in a single deposition pass, while bulk structural components can be fabricated with multiple passes. Deposition geometry is flexible and can be controlled layer by layer.Commercial Applications: In addition to the nuclear structural materials market, initial target markets will focus on industries such as fossil fuel energy where there is a similar need for advanced structural steels. Additionally, there is a demand for ODS materials in the aerospace industry where there is high and demonstratable payoff for weight reduction. The materials developed here could also benefit Navy programs for lightweight ship design and development.