Beijing University of Technology

Tianyang Yan

Wenhao Wang

Lingfei Ji

Lin Li

Rui Ma

Na An

Ximin Zhang

Zhenyuan Lin

The invention disclose a picosecond-nanosecond laser composite asynchronous ceramics polishing method. First, a picosecond laser is used to scan and irradiate the ceramic surface along the scanning path. At the same time, ceramic surface is initially flattened and the electronic state of materials is removed by picosecond laser to produce micro-nanoparticles. Micro-nanoparticles exist as ionized state in the adjacent space region of irradiated ceramics surface. Then, low energy density nanosecond laser is used according to a preset time to irradiate and melt these micro-nanoparticles which can easily form a dense and smooth fine crystal melting layer to achieve the polishing effect. The present disclosure fixes the generation of micro-cracks and pores in traditional laser polishing process. It overcomes the shortcomings of traditional laser polishing such as large thermal influence zone, easy to generate micro-cracks and pores on the surface, etc. High efficiency and high precision submicron level fine polishing with very low material removal amount is realized.

Picosecond-nanosecond laser composite asynchronous ceramics polishing method

The present disclosure relates to a method for high precision laser processing of sapphire with submicron-order section plane using a picosecond-order pulse laser which has high transmittance wavelength to sapphire. The laser triggers ultrafine phase transformation points or electronic state removal points from a lower surface of sapphire. After elevating focal points, a trace which is parallel to laser incident direction is formed. Under a chemical corrosion environment, points of the laser trace are arranged to intersect with other another according to the cutting route to form the corresponding phase transformation region and electronic state removal region. At the same time, by utilizing the catalysis effect of microthermal effect of picosecond laser on chemical corrosion, separation of the sapphire sample along the processing path is obtained. The present disclosure overcomes the limitation of Gaussian beam focusing mode and realizes high precision sapphire cutting with zero tapers and no heat-affected zone. Cutting of hyperfine sapphire and other materials with the high quality cutting surface in micron and submicron ranges with no limitation on the thickness and process path is achieved.

High-precision laser machining method for sapphire submicron-order section

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Beijing, China

Tianyang Yan