CAREER: In-situ Adhesive-less Joining of Thermoplastics and Their Composites to Metals in Net-Shape Processes and an Integrated Design and Processing Education Plan

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9501646 Ramani The primary objective of this research is to develop in-situ processes to join thermoplastic composites to metals in net-shape processes. A hot-melt process and compression molding process will be used as model environments. The surface preparation, contact pressure during consolidation, heating and cooling rates, hold times at melt and recrystallization temperature, effect of bond line thickness and uniformity, and anodization to increase durability will be included in the process development cycle. The residual stresses will be modeled as a function of the process parameters, validated, and then used to improve the process. Known characterization techniques x-ray diffraction (XRD), digital scanning calorimetry (DSC) and scanning electron microscopy (SEM), will be used to evaluate the polymer crystallinity and structure of the interface. The mechanical properties of the joint will be determined. The results will then be applied to filament winding and injection molding and optimized using the models concurrently with experimental characterization. The effects incorporating fibers on the residual stresses and performance of the joint will be determined. Preliminary experimental and modeling results are encouraging. Induction heating will be incorporated to increase the process speeds, reduce polymer residence time at melt, and make the process attractive for applications. At the teaching front, a new curriculum that integrates design and processing will be developed. A synergistic combination of engineering fundamentals, hands-on, modeling, multi-media, inter-disciplinary experiences and industrial perspective will be used. A dual purpose composites processing laboratory will be developed further. The laboratory component of the dual-level composites processing course will be enhanced through the use of interdisciplinary experiences and completed research. A hands-on broad-based materials and manufacturing processes course will be developed with a colleague. The features that distinguish this teaching proposal are development of a new dual-level technical elective in "Design for Processing" (DFP) in conjunction with a "Virtual Processing Lab" (VPL). The DFP course will make strong linkages between design and processing by providing virtual process experiences. This course will integrate demonstrations, process models, and computer tools to provide unique experiences to impact a greater number of students than hands-on courses. The undergraduate teaching plan, research experiences, and training of highly qualified graduate students in the laboratory will have a broad impact and serve future needs of industry. Student research and training will be enhanced through summer employment in the participating industries which will also ease technology transfer. The combined research and teaching programs in design and processing will offer unique experiences to students. By selecting three diverse non-competitive collaborating industries, namely bio-medical, automotive and aerospace major reduction in assembly, tooling and processing costs by reducing the times and steps to manufacture may be seen in applications such as bio-medical implants, suspension linkages, airframe structures, and metal bearing sleeves.