Thrust and torque response for drilling titanium and carbon composite sandwich materials [abstract]

Abstract only availableExperiments were conducted based upon previous research conducted by El-Gizawy and Khasawneh [1] to determine the time response of thrust force and torque correlated to a simple drilling procedure through carbon fiber reinforced epoxy (IM7/997-3) composite material over 6Al-4V titanium alloy (AB1) sheets. The experiments measured the time response with a thrust and torque sensor, data acquisition system and CNC drilling machine. The research was used to locate points of interest among the previous statistical setup. Three-dimensional surfaces were analyzed to determine the drilling parameters that cause the highest force and torque in the CNC spindle (and, therefore, the drill bit) and the lowest force and torque, within the range available with the CNC used in the experimental setup. The experimental holes were also analyzed via surface profilometer and coordinate measurement probe to obtain surface roughness and dimensional accuracy measurements. The data indicates that the parameters that cause lower force and torque are preferable for dimensional accuracy in the titanium as well as for surface roughness, and tool life.College of Engineering Undergraduate Research Optio

Design of an electrical system for swaging targets in the production of molybdenum-99 [abstract]

Abstract only availableMolybdenum-99 is used all over the world to make technetium-99m for use in medical and research fields. The Molybdenum-99 is made by placing low enriched uranium foil in a reactor and allowing it to be irradiated. In order to irradiate the uranium safely, an aluminum target must be assembled to surround the foil. The current process for making these targets is to use a manually powered swaging device. It works by pulling a plug through an aluminum tube assembly which contains the uranium foil. The plug plastically deforms the inner tube and seals the foil inside. This process is time consuming and requires a lot of strength. The idea of using an electrically driven system to swag the tubes was investigated. The required system was analyzed to determine the forces, torque and power needed. A detailed design of the driving system was established and necessary standard components were selected. The new design concept was constructed in a three dimensional solid presentation and in two dimensional drawings. Assembly analysis of different components was conducted in order to assure accurate mating relations among different components

Modeling friction stir welding of Al 2024-T3 [abstract]

Abstract only availableFriction stir welding (FSW) is a modification of the traditional friction welding. It is a process patented by The Welding Institute in Cambridge, England in 1991. It is a mechanical process whereby solid-state welding is performed using heat generated from the friction of a rotating tool. Two plates of metal are butted together and held in place against a backing material using a clamping system. The rotating tool is then slowly plunged with a downward force into the weld joint. It remains stationary for a few seconds while enough heat is generated due to friction that the welded material will begin to flow around the tool. Once this point is reached, the tool is traversed along the joint forming the weld behind the tool as it moves along. The main benefits of friction stir welding come from the fact that the melting temperature of the work piece is not reached during the weld. The mechanical properties of welded metals are retained and even improved when the correct welding parameters are utilized—an area of valuable research as FSW is a relatively new process. By varying the downward plunge force, the depth of the penetration of the tool, the rotation speed of the tool, and the linear velocity at which the tool traverses the joint in the welding process, the optimum mechanical properties of the resulting weld can be obtained. This research is concerned with modeling the temperature distribution in the work piece materials during the weld using analytical methods, based on fluid dynamics method. (GAMBIT/FLUENT). A model of the work piece and tool is created and the calculated amount of heat generated by the friction of the tool is applied to this model. It is important to understand the temperature distribution of the welding process because it directly determines the resulting mechanical properties of the weld. This temperature distribution model is compared to actual experimental data and will help to determine the optimum weld parameters.College of Engineering Undergraduate Research Optio

Target test tube assembly process and design for the development of molybdenum-99 [abstract]

Abstract only availableMolybdenum-99 (Mo-99) is used to create Tc-99, a widely used nuclear medicine diagnostic imaging radioisotope. In an attempt to decrease the need for imported Mo-99, development of mechanical systems to efficiently prepare low enriched uranium (LEU) sheets for radiation is needed. Once prepared, the LEU is radiated to create the Mo-99. This process involves layering the LEU foil between two aluminum tubes, swaging the tubes together, and then sealing the ends. The current design, a die and nut/bolt drawn punch swaging system, and using Tig welding to seal the ends is inefficient and inconsistent. The new mechanical system for the swaging process is designed to be efficient and eliminate any inconsistency. Detailed design of the proposed hydraulic concept was established using 3-D solid modeling software (Pro-Engineer) with 2-D views of non standard parts for future construction. The designed assembly was analyzed for accuracy and proper fits and the entire systems swaging operation was virtually simulated to check for potential errors. The required swaging force was determined through analytical analysis process and initial test measurements. Adequate cylinder, pump, and pressure gauge sizes were determined to exceed the minimum required swaging force. By using a horizontally mounted hydraulic jack to swage the tubes, the applied pressure will be monitored using a pressure gauge to insure a steady swaging force. This design utilizes a sliding die with removable end cap to ease the removal of the swaged tubes. This feature also assists in maintenance and the removal of jammed parts. Using an electron microscope, a gap between the swaged tubes was found using the current punch design. After extensive calculations, a new punch was designed to prevent any unwanted spring back induced gap in the aluminum. To reduce the inconsistency in the tube sealing process, concepts in cold rolling are being further studied