University of Connecticut | |
Faculty
Leon L. Shaw Professor 97 North Eagleville Road
Advanced Hydrogen Storage Materials via Mechanical Activation and Nanostructures: The objective of this project is to establish a scientific foundation for developing mechanically activated, nanoscale, hydrogen storage materials that can meet DOE’s FreedomCAR requirements (i.e., store and release ~ 10 wt% hydrogen at temperatures below 100 C with near ambient pressures). A system approach integrating comprehensive experiments and quantum-chemical modeling has been taken in this project with a focus on Li3N-based and LiBH4-based materials. At the end of this project, a prototype hydrogen delivery system with Li3N-based or LiBH4-based materials possessing ~ 10 wt% reversible hydrogen and capable of delivering 1 kg of hydrogen at ambient temperature and near ambient pressure will be demonstrated. If successful, this program will lead to novel hydrogen storage materials needed to make hydrogen vehicles a reality. (Sponsored by the Department of Energy, Energy Efficiency & Renewable Energy) Functionally Graded Ti/HA Materials for Orthopedic Implant Applications: A new family of functionally graded, porous Ti-6Al-4V/hydroxyapatite (HA) implant materials with a hierarchy of engineered microstructures is being developed through innovative integration of engineering and life science. This new family of orthopedic implants is the first of its kind because they have a Ti-rich core and a HA-rich surface with a controlled level of micro- and macro-porosity. A novel solid freeform fabrication (SFF) method, termed as the slurry mixing and dispensing (SMD) process for making functionally graded materials (FGMs), has been developed to fabricate such a new family of orthopedic implants. Once developed, the carefully designed composition gradients and engineered microstructures will impart to orthopedic implants the excellent corrosion resistance, adequate strength, enhanced mechanical compatibility, and good bioactivity for promoting bone tissue regeneration and fixation of implants. This work is performed under the joint effort with Prof. Yong Wang’s group. WC/Co Cermets with Simultaneous Improvements in Hardness and Toughness Derived from Nanocrystalline Powder: Innovative manufacturing methods that can produce novel materials derived from nanocrystalline powder with low costs and superior mechanical properties simultaneously are investigated. A novel manufacturing process, termed as the Integrated Mechanical and Thermal Activation (IMTA) process, will be utilized to make low cost nanostructured WC/Co powder which will subsequently be densified using the innovative sintering strategy to allow the conversion of nano-WC particles to submicrometer-sized WC platelets. We have teamed up with Kennametal, Inc. to ensure that the research is relevant to hardmetal industry and the result is disseminated to end users. The synergism of this research team will allow us to successfully conduct this innovative project focusing on mechanistic understandings, make contributions to processing and manufacturing technology for microstructure control, and create a new generation of low cost and high performance WC/Co cermets with simultaneous improvements in hardness and toughness. (Sponsored by the National Science Foundation, Engineering Directorate) Synthesis of Nanostructured Si3N4/SiC Materials from Silica Fume: This project aims at processing and fabrication of Si3N4/SiC nanocomposites using the waste material (silica fume) as the starting material. The Si3N4/SiC nanocomposites to be produced in this project are the first of its kind because no such elongated Si3N4 composites reinforced with nano-SiC particles have been produced before. In order to develop such nanocomposites with all the desired properties for high temperature structural applications, the microstructure and interfaces will be properly designed and achieved through novel processing techniques. If successful, this project will lead to (i) an advancement in the processing technique capable of quantity production of high purity nano-Si3N4/SiC composite powders from silica fume in a reproducible, precise and economic fashion; (ii) the establishment of sintering conditions via which Si3N4/SiC nanocomposites with engineered microstructure and interfaces can be produced; and (iii) Si3N4/SiC nanocomposites which are suitable for long-term high temperature structural applications up to 1500 C. The objectives of this project will be achieved through joint efforts with our Egyptian partner, Dr. M. Zawrah’s group at National Research Center, Cairo, Egypt. (Sponsored by the National Science Foundation, Office of International Science and Engineering)
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