Influence of High-Speed Mechanical Vibration and Environments on Precise Laser Machining

With the requirements of smarter, higher energy efficiency and more functional products, there are ever increasing demands for more general and powerful tools that are able to precisely machine small-scale (10 to 500 micro-m) components in a vastly broader range of materials such as crystalline materials (metals, ceramic, semiconductors) and amorphous materials  (glass and many polymers). Thanks to the fast development of solid state and fibre laser techniques over the last two decades, a high-power laser beam can be focused down to a few micro-meters, enabling robust milling of miniaturised features in enormous quality and at a lower cost. The broad wavelength range of spectrum (from deep ultraviolet to far infrared) allows micro-laser machining of a greater array of materials. For example, an ultraviolet laser will directly transform materials from the solid state to plasma and thus limits the size of heat affected zone for temperature sensitive materials. 
The project aims to continue developing a 3D bespoke ultraviolet laser facility that was recently installed at Oxford Micromechanics Group (OMG). An environmental control chamber and high speed vibration system will be integrated into the new laser system. The interactions between an array of solid materials (Ti, Ni and steel) and the ultraviolet laser will investigated in the context of laser fluent, pulse frequency, focused spot size and laser speed. The influence of gases and vacuum on precise laser processing will be assessed in the environment control chamber. EBSD, EDX and nanoindentation will be implemented to characterise the microstructure and mapping the mechanical properties of the laser area and heat affected zone.  The influence of high-speed mechanical vibration, electrical field and alternating magnet fields on precise micro-laser machining, in particular, the depth-to-width aspect of ratio and ablation rate, will be systematically examined in this project.