The effect of billet homogenization on final grain size and texture along with mechanical properties after indirect extrusion of a ZE20 magnesium (Mg) alloy were studied. As-cast and homogenized ZE20 billets were indirectly extruded at 454 degrees C. and an extrusion ratio of 25. Electron backscatter diffraction was used to characterize texture and grain size changes. Quasi-static mechanical testing at room temperature was conducted to determine effects on mechanical properties. The investigation of a thermal treatment on as-cast ZE20 prior to being extruded revealed an increase in ductility as well as a decrease in texture intensity of the homogenized billets.

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Tube hydroforming is a forming method which has several advantages. By using pressure in combination with material feeding it is possible to manufacture products with high structural integration and tight dimensional tolerances. The forming method is especially suited for aluminium alloys which have a relatively low ductility. Finite Element simulations are used extensively in the sheet metal stamping industry, where the methodology has contributed to a better understanding of the process and the new prediction capability has significantly reduced costly die tryouts. Similarly, the tube hydroforming industry can benefit from Finite Element simulations, and this simulation methodology is the topic of this dissertation. Deep drawing and tube hydroforming have a basic difference, namely that the latter process essentially is a force controlled process. This fact, in combination with the anisotropic behaviour of aluminium tubes, enforces a need for accurate constitutive descriptions. Furthermore, the material testing needs to account for the specifics of tube hydroforming. The importance of proper material modelling is in this work shown for hydrobulging and hydroforming in a die with extensive feeding. The process parameters in hydroforming are the inner pressure and the material feeding, where a correct combination of these parameters is crucial for the success of the process. It is here shown, that Finite Element simulations together with an optimisation routine are powerful tools for estimating the process parameters in an automated procedure. Finally, the reliability and quality of the simulation results depend on how failure is evaluated, which in the case of hydroforming mainly oncerns wrinkling and strain localisation. Since tube hydroforming often is preceded by bending operations this fact also demands the criteria to be strain path independent. In this work, it is shown that the prediction of strain localisation depends on the ability to predict diffuse necking, which in turn is strongly related to the chosen constitutive model.

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Uppsatsen behandlar bullerdämpning vid kap på ProfilGruppen Extrusions AB i Åseda. Problemen med ljudnivån beror bland annat på stomljudet som alstras av kapen i de långa profilerna. För att sänka ljudnivån har fastklampningskonstruktioner tagits fram som dämpar stomljudet och förslag på vidare åtgärder rapporterats. Försök och jämförande mätningar av ljudnivån har utförts för att få ett bra underlag att utvärdera. Resultaten av försöken med viskoelastisk plast som dämpelement visar en viss dämpning. Dämpningen kan med all sannolikhet bli större med användning av tjockare dämpelement. / This project is about noise reduction of a cross cut saw at ProfilGruppen Extrusions AB, Åseda. The problems with the sound level depend on the structure-borne sound that generates in the long profiles. To lower the sound level have press clamp constructions been developed which reduce and further attends have been suggested. Attempts and comperative measurings of the sound level have been evaluated. The results of the comperative measurings with viscoelastic plastic as damping element display certain damping. The damping can in all probability become larger using a thicker damping element.

<p>Uppsatsen behandlar bullerdämpning vid kap på ProfilGruppen Extrusions AB i Åseda. Problemen med ljudnivån beror bland annat på stomljudet som alstras av kapen i de långa profilerna. För att sänka ljudnivån har fastklampningskonstruktioner tagits fram som dämpar stomljudet och förslag på vidare åtgärder rapporterats.</p><p>Försök och jämförande mätningar av ljudnivån har utförts för att få ett bra underlag att utvärdera. Resultaten av försöken med viskoelastisk plast som dämpelement visar en viss dämpning. Dämpningen kan med all sannolikhet bli större med användning av tjockare dämpelement.</p> / <p>This project is about noise reduction of a cross cut saw at ProfilGruppen Extrusions AB, Åseda. The problems with the sound level depend on the structure-borne sound that generates in the long profiles. To lower the sound level have press clamp constructions been developed which reduce and further attends have been suggested.</p><p>Attempts and comperative measurings of the sound level have been evaluated. The results of the comperative measurings with viscoelastic plastic as damping element display certain damping. The damping can in all probability become larger using a thicker damping element.</p>

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The rising cost in video game content creation, both in terms of man hours and in terms of monetary dollars, restricts the ability of video game developers to create unique, entertaining content. Motivated by how this cost is a direct result of "next-generation graphics", I am motivated to ask: what would a next-generation content creation tool look like? I investigate the problem by constructing several such tools. In particular, I construct a mesh quilting algorithm for random level generation, a rapid level construction toolkit based on the concept of an architectural blueprint but supporting features such as complex silhouette geometry and roof geometry, and a tool for rapidly painting world textures. I also introduce a new system for accessing barycentric coordinate data from within the fragment shader, which can be used in support of real-time 3D image quilting, more accurate normal interpolation, and texture rendering from within the world painting tool. Some history of video game content creation is discussed, and a roadmap is charted for future development. / Graduate

Friction Stir Welding (FSW) was used to perform Bead on Plate (BOP) welds on 6061-T6511 aluminum extrusions. Using a DOE approach, tool rotation speed, clamp spacing, and clamping force were altered to ascertain their effects on distortion in the welded panels. Mechanical forces were monitored during the weld process. Both linear and out of plane distortion were measured on the welded extrusions. The Vickers hardness of the weld nugget was measured. The effect of each parameter on weld distortion was discovered and the mechanism of this link was suggested.