LAMDA: Irradiated-Materials Microscopy at Oak Ridge National Laboratory

Abstract

Oak Ridge National Laboratory's Low Activation Materials Development and Analysis (LAMDA) laboratory is a dedicated facility containing specialized instruments for the study of irradiation-induced effects on materials properties. Located in the Materials Science and Technology Division, LAMDA consists of several interconnected contamination-zone and clean area suites. Originally created as a facility for plutonium studies and then thermophysical properties of graphite for high temperature gas cooled reactors in the 1960's, the role of LAMDA has changed with the emphasis placed on "low activation" materials. Currently, LAMDA is involved in both fundamental and applied research on radiation-induced changes in structural materials, reactor internals, diagnostic materials and sensor components for both current and advanced reactor designs for both fission and fusion systems. LAMDA allows for the examination of low activity radiological samples (< 100 mR/hr at 30 cm) without the need for remote manipulation. LAMDA typically utilizes small, compact samples to allow researchers to leverage cutting-edge characterization and test equipment to study materials phenomenon not possible at a hot cell facility. The LAMDA facility is maintained as a low alpha contamination facility, but certain equipment is available for fuel-related studies. LAMDA contains a strong electron microscopy subprogram, which we describe here.A full complement of equipment and instruments are available for metallographic and microstructural analysis of materials. This includes X-ray tomography and three irradiated-materials-dedicated FEI DualBeam FIB-SEM instruments for 3D materials studies and the preparation of specimens for TEM. LAMDA contains a new 200kV Schottky JEOL JEM-2100F S/TEM with EDS and Gatan Quantum Image Filter, and leverages ORNL's other TEM tools as well as SEMs and atom probe.The LAMDA lab works in conjunction with the Irradiated Materials Examination and Testing (IMET) and Irradiated Fuels Examination Laboratory (IFEL) hot-cell facilities at the laboratory to study materials irradiated at either the High Flux Isotope Reactor (HFIR) or other experimental and commercial reactors. The LAMDA, IMET, IFEL and HFIR facilities are all part of the National Science User Facility. LAMDA performs work supported by various Department of Energy (DOE) programs including the Fusion Materials, Light Water Reactor Sustainability, DOE-Naval prime contractors, as well as collaborations with other international research facilities, universities and companies. Figure 1 shows the IMET facility, where irradiated capsules are opened and the specimens sorted and subjected to first-stage preparation (e.g., inspection, cutting, grinding). Figure 2 shows one of the FEI DualBeam instruments, which is located in a lead-shielded room and equipped for remote operation, and can be used to prepare TEM specimens of irradiated fuels. Figure 3 shows the newly installed JEOL 2100F TEM/STEM instrument. Figure 4 shows Re-rich precipitates in HFIR-irradiated tungsten that ...

A combined APT and SANS investigation of α′ phase precipitation in neutron-irradiated model FeCrAl alloys

“…Following room-temperature mechanical testing, standard metallography techniques were used to mechanically polish single fractured half tensile specimens for focused ion beam (FIB) sample preparation. Atom probe needles were prepared using the FIB lift-out method [41] from the non-deformed head areas of the half tensile specimens at the Low Activation Materials Development and Analysis facility at ORNL using an FEI Quanta 3D dual-beam FIB [42]. Liftouts were prepared from each of the four FeCrAl compositions at the 7.0 dpa condition in addition to the unirradiated, 0.8 dpa and 1.8 dpa conditions of the Fe-18Cr-5.8Al composition.…”

Reliable Method to Detect Alloy Soldering Fractures under Accelerated Life Test

“…These types of alloys do not satisfy certain requirements of the 17 electronic components, forming ternary and quaternary alloys. Yang et al [5], Parish et al [6], Li et al [7], and Wu et al [8] mentioned that the most important tin ternary alloys are tin, silver, and copper (SnAgCu) and tin, silver, and bismuth (SnAgBi).…”

“…In the Arrhenius acceleration model and Ideal Gas Law, the Boltzmann's constant (k) has a value of 8.6×10 −5 = 0.0000086 scale = 365 84.42 = 4.32 (6) For the performance of the test vibration in a simulator, Shaker Tira Vib and a signal generator were used. This signal generator establishes the frequency and the width in which the Shaker will vibrate.…”

“…A ductile fracture occurs when the soldering alloy is exposed to plastic deformation due to stress caused by damage including excessive tensions such as thermal variation or mechanical effort. In some research [6][7][8][9][10][11][12][13], it is mentioned that mechanical effort causes parallel cracks, and thermal variation generates a network of multiple fissures. Furthermore, there have been fracture analyses using measures of resistance and visual inspection.…”

“…Certain authors have analyzed the different failures originating in soldering alloy. Parish et al [6] observed that fluctuation in temperature caused expansions in the soldering alloy, generating additional stress and degradation. Due to this, there have been development tests that determine the capacity of a soldering alloy to resist thermal fatigue.…”