b'Micromechanical testing of FeCrAl weldsPrincipal Investigator: Jonathan Gigax (MPA-CINT, LANL)Team Members/Collaborators: Nan Li (MPA-CINT, LANL) and Stuart Maloy (MST-8, LANL)The developedB ecause of the events related tovaluable advancements and insights, the Fukushima reactor incident,notably in small scale mechanical mesoscale mechanicalinnovative new cladding mate- testing (SSMT). The need for larger testing techniquerials are being investigated for Lighttests that include more material and systems deliverWater Reactors (LWRs) with improvedvolume and microstructural defects bulk-like mechanicalresistance to accident conditions suchhas been recognized, and motivated behavior at sizes ordersas a Loss of Coolant Accident (LOCA).our foundational work to develop of magnitude smaller,Materials need to be developed andmesoscale mechanical testing enabling localized testingtested to meet these challengingplatforms. These systems target of various mechanicalconditions. Some engineering alloysspecimen sizes on the order of 10s properties includingare presently available with promisingto 100s of micrometers. However, strength and ductility. properties but these alloys werespecimen preparation, especially at not specifically developed for LWRthe larger end of the scale, proved applications. Thus, researchers at Loschallenging for conventional Alamos National Laboratory (LANL)techniques, such as focused ion beam are continuing development of a new(FIB) and wire electro-discharge improved accident tolerant fuel (ATF)machining (EDM).cladding material (FeCrAl) in collabo- We (LANL and UC-Berkeley) developed ration with Oak Ridge National Labora- techniques using femtosecond tory (ORNL) and performing microlaser ablation to prepare a range and mesoscale mechanical testing onof geometries commonly used in cladding and welds for this alloy. mechanical testing including pillars, Project Description:tensile bars, and cantilevers (Figure ATF FeCrAl alloys are being developed1) [1]. The principle advantage of at ORNL with optimal elementalthis approach is the rapid removal constituents. Significant progress hasof material that can access material been made in optimizing the alloythicknesses on the order of millimeters. composition of Gen I and Gen IIHowever, the process is not damage FeCrAl alloys and the optimum alloy isfree. Damage induced by the C26M. LANL is performing micro- andfemtosecond laser ablation is minimal mesoscale mechanical testing on heats(less than 5 m in pure Cu), making of C26M, including welds, to comparethis a choice technique for coverage properties to previous alloys.over a large range of sizes [2].Accomplishments: After establishing laser processing Projects and studies undertakenprocedures, our attention focused through the Advanced Fuels Campaigntowards investigating engineering (AFC) have yielded a number ofmaterials subject to conventional 74 2020|AFC ACCOMPLISHMENTS'