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Department of Materials Science & Engineering
Show moreThe focus of this research was to determine a milling procedure to help facilitate the Cr2Nb transformation. The metric to evaluate a facilitated phase transformation was a reduction in endothermic onset temperature during Differential Scanning Calorimetry (DSC). The transformation of the Cr+Nb powder to Cr2Nb alloy is diffusion dependent, therefore by creating more intimate contact the elements will be closer together. A reduction in spatial distance for a diffusion-based reaction will lead to a reduction in total time for the reaction to complete. The design of a multi-stage milling process allows the refinement of the powder particle size so that diffusion can more easily occur at a lower temperature. The effectiveness in powder size reduction was tested for two bearing sizes to determine the required milling time for each stage. It was determined that dry milling elemental Cr powder for 5 minutes with 4.88mm bearings and then wet milling for 3 minutes with 2.47mm bearings produced a size distribution with a D90 less than 25𝜇m. After determining this 2-step milling procedure, a mixture of Cr+Nb powder was milled with the 2-step process and compared with Cr+Nb powder that had been milled with a 1-step process. X-Ray Diffraction (XRD) was done on the mixtures before DSC and the results showed the presence of elemental Cr and Nb. These two mixtures were then exposed to a controlled heating rate of 20 degrees C per minute up to 1400C in a Netzsch Pegasus 404 F1 DSC and then cooled. Post-DSC, the XRD results showed a significant increase in the presence of Cr2Nb alloy. Therefore, the endothermic reaction visible in the DSC results must have been the phase transformation from elemental Cr and Nb to Cr2Nb alloy. In comparing the 1-step and 2-step milling processes, the DSC results show that the transition temperature of the Cr+Nb powder was reduced from 1229C to 1089C when the milling was changed from 1-step to 2-step. Future research will investigate the effects of such milling on the in-situ formation of Cr2Nbduring additive manufacturing processes.
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Show moreThe first half of the 16th century saw an international religious and cultural conflict that rose within Western Christianity between Roman Catholics and the newly established Protestants. Key figures such as Martin Luther and Jean Calvin challenged papal authority and the Catholic church’s ability to define Christian practice thus instigating the Protestant Reformation. Within church confines differences in values and beliefs such as the legitimacy of purchasing salvation through indulgences or interpretations of the Eucharist transformed the spaces in which Protestants practiced their new version of Christianity. As a result of this split, Lutherans encouraged the display of a restricted range of religious images through an adherence to the Ten Commandment’s prohibition of idolatry and creation of sculpted images of God. Overt religious images in public spaces and churches were subject to attacks from the most radical iconoclasts. Often religious artworks were commissioned through private enterprise allowing for the preservation of select works to remain untouched to this day. This exhibition aims to expose the transition of church elements and design through a replication of the first Protestant cathedral and a collection of artworks seen within these sacred spaces or related to the region. The Torgau Castle Chapel was consecrated by Luther himself. Within its barren white and gold accented walls the modest chapel features three lone elements, a grand organ, a white stone altar and an elevated ornate pulpit. The interior space differs considerable with the Brussels Cathedral. Under the strict jurisdiction of the heavily Catholic Spanish Empire, this massive cathedral houses a wide array of stained glass windows and atlantes of the twelve apostles on par with Catholicism’s incorporation of religious images aiding in worship. Through an analysis of visual elements present within the Brussel Cathedral and the Torgau Castle Chapel, conclusions can be drawn about this initial religious impetus to further explain how Northern Europeans evolved to further define their religious spaces to accommodate a changing belief system. In addition, a supplemental collection of objects and artworks from a number of locations will further illustrate the Protestant Reformation’s effect on Northern European renaissance art. Ultimately, this comprehensive exhibition space mockup touches upon both aspects of exhibition design and curatorial work.
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