Title: Femtosecond laser micromachining of zirconia green bodies

Authors: Hyesung Shin; Wonjong Jeong; Youngsam Kwon; Dongsik Kim

Addresses: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea ' Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea ' Cetatech, Sacheon 664-953, South Korea ' Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea

Abstract: In this study, we developed micromachining processes using a femtosecond Ti: sapphire laser for zirconia green bodies, i.e., composites comprising zirconia particles and polymer binders. The laser ablation characteristics of the zirconia composites were analysed to optimise the process. In comparison with bulk zirconia, ablation of the zirconia green bodies occurred at lower fluences. In the high-fluence regime, laser irradiation directly ablated the zirconia particles, causing aggregation of resolidified particles. The ablated depth increased with fluence (F) and overlap number (N) initially, but saturated when F and N became larger. Microchannels with a minimum width of 4 µm were fabricated. The microchannel width decreased with decreasing fluence and overlap number. Microholes, microchannels and three-dimensional structures with a size of several tens of micrometres and aspect ratio of 5-15 were successfully fabricated using the zirconia composite.

Keywords: femtosecond laser micromachining; powder injection moulding; PIM; zirconia green bodies; zirconia composites; laser ablation; microholes; microchannels; microstructure.

DOI: 10.1504/IJASMM.2017.082992

International Journal of Additive and Subtractive Materials Manufacturing, 2017 Vol.1 No.1, pp.104 - 117

Received: 31 Mar 2016
Accepted: 06 Oct 2016
Published online: 17 Mar 2017 *