Sökning: "localized etching"
Visar resultat 1 - 5 av 11 avhandlingar innehållade orden localized etching.
1. Heterogeneous Integration of Shape Memory Alloysfor High-Performance Microvalves
Sammanfattning : This thesis presents methods for fabricating MicroElectroMechanical System (MEMS) actuators and high-flow gas microvalves using wafer-level integration of Shape Memory Alloys (SMAs) in the form of wires and sheets. The work output per volume of SMA actuators exceeds that of other microactuation mechanisms, such as electrostatic, magnetic and piezoelectric actuation, by more than an order of magnitude, making SMA actuators highly promising for applications requiring high forces and large displacements. LÄS MER
2. Wafer-level heterogeneous integration of MEMS actuators
Sammanfattning : This thesis presents methods for the wafer-level integration of shape memory alloy (SMA) and electrostatic actuators to functionalize MEMS devices. The integration methods are based on heterogeneous integration, which is the integration of different materials and technologies. LÄS MER
3. An Insight into the Critical Role of Microstructure and Surface Preparation on Localized Conversion Coating Deposition on Cast Al Alloys
Sammanfattning : The spontaneous cerium conversion coating formation over aluminium alloys is affected by the chemical process conditions, the surface preparation prior to conversion treatment and the microstructure of the underlying alloy. Most research performed until now focus only on the former whereas the influence of the latter two is poorly understood. LÄS MER
4. The influence of Al alloy microstructure on conversion coating formation
Sammanfattning : The formation of conversion coatings based on Ce, trivalent Cr and Ti/Zr is triggered by the local pH increase at cathodic IM sites of the aluminium alloy microstructure. The pH gradient is created over the cathodic intermetallic (IM) sites of the microstructure and its intensity is influenced by their activity which depends on their chemical composition, their size, and spatial distribution. LÄS MER
5. Microstructure and deformation behaviour of ductile iron under tensile loading
Sammanfattning : The current thesis focuses on the deformation behaviour and strain distribution in the microstructure of ductile iron during tensile loading. Utilizing Digital Image Correlation (DIC) and in-situ tensile test under optical microscope, a method was developed to measure high resolution strain in microstructural constitutes. LÄS MER