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Draw a schematic sketch of a tensile test (stress-strain curve) of a titanium alloy (elastic modulus 100GPa, tensile strength 1.000MPa, strain at break 20 %). How can you determine the 0,2%-yield strength from such a stress-strain-curve?
A medical implant with a square cross-section of 1x1mm^2? is made from this material. What is the maximum force (in N) such an implant can carry, assuming above tensile strength and a safety factor of 3? -
Define the terms Stiffness, Strength, Hardness, and Fracture Toughness. How does the deformed volume (V), the Flow stress (σ_f) and the Strain at break (E) influence the dissipated energy (W_p) during crack growth?
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Explain why low melting materials have a larger coefficient of thermal expansion than high melting materials by drawing the binding energy versus atom distance for both types of materials.
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Which 4 mechanisms are available for the strengthening of metals? Provide a brief explanation of each mechanism. How is toughness influenced by strengthening for individual mechanisms?
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Due to the very high strength and fracture toughness, zirconia is a widely used framework material in dentistry. Explain in detail the mechanism responsible for zirconia’s high fracture toughness.
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How are polymers classified in terms of morphology? Draw the elastic modulus versus temperature diagram for each of the 4 classes and describe their properties.
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Additive Manufacturing is a new processing method that can be used to produce dental restorations. What are the typical parts of a 3D printer used in a Lithographic Ceramic Manufacturing process (LCM) and what are the steps and (chemical) components required to print a ceramic part?
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What are the 3 functions of packaging for sterilization? Explain them briefly with some examples.
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Which International Standards (ISO) guidelines cover the „Biological evaluation of medical devices“? Name 3 subcategories if this ISO norm. Describe in detail one assay or test that appears in these guidelines.
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What are the 5 phases of the foreign body response, which biomolecules/cells are key players in each and what are approximate timeframes of each phase?
Total Points: 50
Time Allotted: 90 (not enough!!!)