Very high cycle fatigue mechanisms in small scale Al and Cu and alloy material investigated by simulation and novel uniaxial and multiaxial micro fatigue experiments

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The aim of this proposal is to understand the active fatigue mechanisms in Al, Cu, Fe and alloys in small volumes. Even though such materials are widely used in safety relevant applications (sensors, micro and powerelectronics), only little research can be found on reliability. Since scaling and size effects will change the fatigue behavior of small scale materials, modells and know-how from the macro world cannot be easily transfered to the micro world.Recent experimental results from the forst phase of the SPP1466 suggest that a stochastic model could be used to reliably describe the materials' properties. Spcifically, the orientation of neighboring grains plays a significant role in the fatigue induced damage process. Therefore, one focus will be to understand local damage formation which will be backed up by discrete dislocation dynamics simulations of grain agglomerats. The experimental possibilities shall be enhanced by a second setup which should be vacuum compatible to be used in a vakuum chamber to reduce air friction and improve precission or in an SEM to do in-situ fatigue testing. Besides fcc metals and their alloys, also bcc metals will be tested and simulated to get a stronger connection to other members of the SPP1466.