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Lewicki, James

Publications and source records attributed to Lewicki, James.

Fluoropolymer Aging Assessments

Fluoropolymer (FP) binders are commonly only a few percent of polymer bonded explosive compositions but they are essential for the mechanical integrity of the part. Because we are using newly manufactured binders, we need to understand how lot variations might affect processing, aging, and mechanical properties. Time, temperature and radiation induce phase changes in fluoropolymers. These phase changes can rearrange the polymer causing crystalline domains to nucleate and grow that can alter mechanical properties. These studies quantify the aging process so that it may be cross correlated with changes in the adhesion, strength, and other properties important for performance.

36 MATERIALS SCIENCE↗

Optimal toolpath generation system and method for additively manufactured composite materials

The present disclosure relates to a system for optimizing an additive manufacturing (AM) process. The system may use a printing component for using a material to form a component in a layer-by-layer process. An electronic controller may control movement of one of the printing component or a substrate on which the component is being formed, in a manner to optimize a toolpath for the printing component as each layer of the component is formed. Optimization operations are performed using an optimization subsystem which enables manufacturability constraints, as well as optimized toolpaths for each layer of the component, to be defined using contours of a level-set function. The level-set function may be used to define the optimized toolpaths within a fixed, predetermined grid, and the optimized toolpaths then used to generate suitable code for controlling movement of the printing component relative to the substrate to create the part or structure in a layer-by-layer process, using the optimized toolpaths.

Lewicki, James↗

High performance, rapid thermal/UV curing epoxy resin for additive manufacturing of short and continuous carbon fiber epoxy composites

An additive manufacturing resin system includes a container; a build platform in the container; a build platform drive; an additive manufacturing resin that forms an additive manufacturing resin bath; an additive manufacturing print head; a build material supply connected to the additive manufacturing print head; an infill resin in the container, wherein the infill resin is supported by the additive manufacturing resin bath; a computer controller; and an extruded material that forms the product, wherein the infill resin at least partially surrounds the extruded material that forms the product. An infill resin supply provides the infill resin into the container and a control valve is connected to the infill resin supply. An IR light sensor is connected to the control valve and operatively connected to the infill resin in the container.

Lewicki, James↗