The impact of the chemical structure on ion transport, nanoscale morphology, and dynamics in polymerized imidazolium-based ionic liquids is investigated by broadband dielectric spectroscopy and X-ray scattering, complemented with atomistic molecular dynamics simulations. Anion volume is found to correlate strongly with T g-independent ionic conductivities spanning more than 3 orders of magnitude. In addition, a systematic increase in alkyl side chain length results in about one decade decrease in T g-independent ionic conductivity correlating with an increase in the characteristic backbone-to-backbone distances found from scattering and simulations. The quantitative comparison between ion sizes, morphology, and ionic conductivity underscores the need for polymerized ionic liquids with small counterions and short alkyl side chain length in order to obtain polymer electrolytes with higher ionic conductivity.

The formation of defects within additive-manufactured (AM) components is a major concern for critical structural and cyclic load applications. Thus, understanding the mechanisms of defect formation in fusionbased processes is important for prescribing the appropriate process parameters specific to the alloy system and selected processing technique. This article discusses the formation of defects within metal additive manufacturing, namely fusion-based processes and solid-state/sintering processes. Defects observed in fusion-based processes include lack of fusion, keyhole collapse, gas porosity, solidification cracking, solid-state cracking, and surface-connected porosity. The types of defects in solid-state/sintering processes are sintering porosity and improper binder burnout. The article also discusses defect-mitigation strategies, such as postprocess machining, surface treatment, and postprocessing HIP, to eliminate defects detrimental to properties from the as-built condition. The use of noncontact thermal, optical, and ultrasound techniques for inspecting AM components are also considered. The final section summarizes the knowledge gap in our understanding of the defects observed within AM components.

The formation of defects within additive-manufactured (AM) components is a major concern for critical structural and cyclic load applications. Thus, understanding the mechanisms of defect formation in fusion-based processes is important for prescribing the appropriate process parameters specific to the alloy system and selected processing technique. This article discusses the formation of defects within metal additive manufacturing, namely fusion-based processes and solid-state/sintering processes. Defects observed in fusion-based processes include lack of fusion, keyhole collapse, gas porosity, solidification cracking, solid-state cracking, and surface-connected porosity. The types of defects in solid-state/sintering processes are sintering porosity and improper binder burnout. The article also discusses defect-mitigation strategies, such as postprocess machining, surface treatment, and postprocessing HIP to eliminate defects detrimental to properties from the as-built condition. The use of noncontact thermal, optical, and ultrasound techniques for inspecting AM components are also considered. The final section summarizes the knowledge gap in our understanding of the defects observed within AM components.

The University of Texas at Austin as an account of work sponsored by the Lawrence Livermore Laboratory (LLL) under subcontract No. 1823209. Neither LLL, members of LLL, The University of Texas, nor any persons acting on behalf of either: (a) makes any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method or process disclosed in this report may not infringe privately owned rights; or (b) assumes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method, or process disclosed in this report. ABSTRACT A preliminary engineering design of a compensated pulsed alternator for driving laser flashlanps is presented. The work performed by the Center for Electromechanics at The University of Texas at Austin also includes the optimization and revision of the prototype design for a compensated pulsed alternator power supply for the NOVA laser system at Lawrence Livermore Laboratory, BIRD UT-CEM LLL 11-30-78 96 15mm x M2cr

Laser-based directed energy deposition (LDED) for repair and sustainment has become a viable alternative to replace or complement traditional repair applications. Many a time, thin-walled structures cannot be repaired because of the heat intensive repair operations, which lead to excessive distortion or degradation of the parent material. To overcome repair challenges related to thin-walled structures, a low-energy process strategy with powder feedstock has been developed to reduce the heat-affected zone, reduce distortion, and produce a microstructure yielding higher microhardness values. On the other side of the repair spectrum, much larger surfaces may also need attention. In this case, a high-deposition rate process strategy may be more suitable to reduce lead-time and cost. To accommodate larger repairs, a high-deposition rate process strategy using wire feedstock has been developed. The high-deposition rate strategy is shown to be more cost-effective provided the target application and part geometry can accommodate the high-energy process. Validating these LDED repair strategies has been accomplished by analyzing the resulting distortion, presence of flaws or defects, microhardness, microstructure, and tensile properties. The process control offered by LDED through the ability to tailor the process-structure-property relationships of a material system depending on component geometry and application has put a new tool in place addressing many concerns related to traditional arc-based repair processes.