b'Bridging the Length Scales on Mechanical Property EvaluationPrincipal Investigator: Peter HosemannTeam Members/ Collaborator: Andrew Dong, Hi Vo, Jason Duckering, Eric Olivas, Assel Aitkaliyeva, Tanvi Ajantiwalaynumber of samples and tests thatAccomplishments:can be performed for a finite volumeA major aspect of this research is to Micromechanical testingof material. This is particularlyobtain micromechanical data from is becoming a part ofrelevant to the monitoring of reactormaterials spanning a wide range of the nuclear materialscomponents as in-service surveillancematerial conditions and microstruc-examination toolboxtesting has limited material due totures. To this end, micromechanical and this research showsboth space constraints as well astesting has been performed on the scaling effectsrepresentative sampling conditions.materials containing different associated with specificEx-service components similarlydegrees of dislocation densities microstructural features. have constraints over the amount(pure nickel and various heats of of volume available to examine.Alloy 600), precipitates (different Through increased statistics andheats of CuCrZr provided by the T he development of small-scaletargeted investigations into materialUnited Kingdom Atomic Energy mechanical testing in combi- properties, small scale testing canAgency), and grain sizes (different nation with microstructuraltherefore be invaluable to continuedheats of 304SS). Results from this investigation is of great interest tooperation of the nations currentwork includes the introduction the nuclear materials communityreactor fleet and the design of nextof the blocked volume concept for both materials developmentgeneration reactors. evaluating the effect of constraint and monitoring applications. ThisHowever, much work needs to beon micromechanical testing results research aims to bridge the lengthdone in order to establish confidence(Hi Vo, University of California, scale of material property evaluationin drawing application scaleBerkeley). This concept is detailedand thus enhance the confidence inconclusions from small scale data.in Figure 1.using data obtained from microscaleThis involves the developmentFurthermore, testing of ion-irradiated testing to macroscale applications.of data collection and analysisHT-9 (from Idaho National Laboratory Work performed involves micro- techniques at the small scale asobtained via Los Alamos National mechanical testing of a wide varietywell as demonstrating the fidelityLaboratory) was performed. A subset of nuclear-relevant material micro- in derived micro- to macroscaleof the samples tested include HT-9 structures as well as developingscaling relationships. It is thesamples that were irradiated at novel testing and analysis techniquesobjective of this research to obtainSandia National Laboratory using to bridge work across length scales. small scale mechanical data from4MeV protons to doses levels of a variety of different materials7E-5, 7E-4 and 7E-3 dpa (Tanvi Project Description: and microstructural features andAjantiwalay, University of Florida). Small scale mechanical testingexpand the state-of-knowledge onThese results are shown in Figure 2 (100m, commonly 10m) has significant advantages for materialshow these smaller scale featurescomparing unirradiated HT-9 to the research. It enables isolation andinfluence the properties of a material. ion-irradiated HT-9.probing of specific microstructuralSimultaneous development of testingAlso performed is a thickness study regions and features of interest.and analysis techniques aim toon tensile properties for a variety Furthermore, it increases thebridge gaps length scale examinations. of the aforementioned materials 40 2022|AFC ACCOMPLISHMENTS'