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Current Research Groups
Current researchactivities of the lab focus on the manufacturing of advanced cutting edge
materials like ceramics, composites and titanium etc., with an emphasis on
material removal, surface treatment, and assembly processes.
Abrasive Waterjet Machining:Cutting edge innovative applications of ultra-high-pressure waterjet processes at 600 MPa are under investigation. High pressure processes of focus have been surface preparations, surface texturing, and the related subsurface modifications. Research to date has been centered on aerospace materials, with specific investigations into surface preparations as applied medical implant materials, and coating removal applications.
Research Students: Alex Chillman, Inkwon Hwang
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Friction-Stir Welding and Super Plastic Forming:Advanced welding and metal forming processes are currently being investigated as a means of producing large monolithic structures for aerospace applications. A collaborative multi university and industry effort has been conducted to develop the Friction Stir Welding (FSW) process for titanium 6Al-4V and then combining it together with Superplastic Forming (SPF) to build extremely large sheet metal assemblies. Initial testing has shown that high strength titanium FSW butt-weld joint can be made without any melting of the parent metal. In fact, heating of the weld zone can be kept below the beta transus limit of the workpiece material. This has permitted subsequent bi-axial SPF across the FSW joint to elongations in excess of 200%. In addition to process development, several other FSW and SPF research projects are underway, including analytical process modeling, numerical analysis, tooling development, fine grain titanium alloy research and experimental characterization of the product.
Research Students: Dan Sanders, Paul Edwards, Trent Greenwell, Andrew Cantrell
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Machining and Surface Integrity Studies of Advanced composites:Composite materials are inherently prone to induced damage, both exterior as well as unseen internal damage, and both at the micro and macro length scales. This damage can result in a substantial degradation of material strength properties. The degradation typically results from every stage of the manufacturing process, from the conception of the material at the cure stage to the post-processing cutting, trimming and drilling operations performed in order to meet design allowables. This research involves a study of the typical damage induced from these various manufacturing operations on composite materials and their correlation with the strength degradation and activated failure mechanisms upon impact loading. Applications of research are primarily in the aerospace, automotive and recreational industries. A fundamental analytical investigation of the stress-fields in the cutting zone during the orthogonal cutting of FRP laminates is being conducted using the tenets of anisotropic elasticity and composite Equivalent Single Layer (ESL) theories in order to understand the physics of machining of FRPs. More realistic drilling process is also being looked into to understand the delamination phenomenon often associated with drilling the last few plies of a FRP laminate.
Research Students: Suhasini Gururaja, Timothy Briggs, Girum Gebremariam, Jeremy Stewart
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Surface Modification effects on Fatigue and Fracture behavior:In automotive and aircraft industries, there are huge uses of aluminum alloy and titanium alloy. Aluminum alloy has a high strength and low density as compared to steel. However, the fatigue strength of aluminum and titanium alloy does not match with the desired one of industry. In aerospace and automotive industries, it is well known that improving fatigue strength of cyclic stressed parts is the main goal. To improve fatigue strength of cyclic stressed parts, shot peening to produce the beneficial compressive residual stress on the surface of these parts was introduced. This investigation studies the surface modification or treatment by peening process in terms of shot peening parameters, existing mathematical and numerical models, effects of residual stresses, microstrucres, and surface roughness on fatigue life and also predicts what combinations yield the best fatigue life.
Desired surface properties such as high hardness, wear resistance, corrosion resistance, and resistance to oxidation are usually not found in bulk materials such as carbon steel or aluminum. To achieve the desired properties, the surface layer of the material can be modified. Plasma sprayed and laser treated Inconel has been used to enhance the wear resistance of carbon steel. The objectives of this research are to investigate the wear resistance of carbon steel that has been coated with Inconel powder.
Research Students: Heechang Bae, Daniel Alkazar, Matthew Beck, Julio Davis
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