The mechanism behind third order intermodulation distortion (IM 3 ) in capacitively driven clamped-clamped beam micromechanical ("CC-beam µmechanical") resonators is shown to arise mainly from nonlinear interactions between applied off-resonance electrical signals and the mechanical displacements they induce. Analytical formulations for the third-order input intercept point (IIP 3 ) are then presented, first with simplifications that allow a closed form expression, then with additional complexities to account for second-order effects, such as beam bending due to an applied dc-bias voltage. Using this analytical formulation, predicted voltage IIP 3 's of 1.8V and 6.5V for 9.2 MHz and 17.4 MHz µmechanical resonators, respectively, closely match measured values of 1.8V and 6.3V. Extensive data on the dependence of IIP 3 on dc-bias voltage, resonator Q, and resonator center frequency, are also included to lend further insight into the trade-offs involved when designing for a specific linearity requirement.

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Two different protective MCrAlY (NiCrAlY and NiCoCrAlY) coatings were obtained using the Atmospheric Plasma Spray (APS) method on the Inconel 718 substrate. It is aimed to inspect the rate of erosion and increase working life in last stage components of gas turbines, turbine blades and vanes. Because of the nature of exhaust, they are exposed the high temperature solid particle erosion. The High Temperature Solid Particle Erosion (HTSPE) test rig, which was specially designed and manufactured in accordance with the internationally accepted standard of ASTM G211-14, was used in the experiments. The experiments were conducted with three different air temperatures (room temperature, 300 °C and 600 °C), three different erosive particle impact angles (30°, 60°and 90°), constant particle impact velocity (∼97 m s −1 ) and particle size (400 μm Al 2 O 3 ). SEM images, XRD analysis, EDX mapping and EDX element analysis were used to characterize the coatings. The erosion resistance results were interpreted with respect to the porosity values, hardness and surface roughness measurements of the coatings in details. As a result of the experiments, MCrAlY coatings showed ductile material behaviour compatible with erosion wear, and the cobalt element added to the coating structure contributed positively to increasing erosion resistance.

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