Precise micromachining of yttria-tetragonal zirconia polycrystal ceramic using 532 nm nanosecond laser

High quality micro-sized steps and blind hole structures without microcracks, chips or spatter deposition were machined on yttria-tetragonal zirconia polycrystal (Y-TZP, 3 mol% yttria) by nanosecond laser (wavelength=532 nm, pulse width ~6 ns). The diameter of blind hole is 500 μm and each step is 500±10 μm wide and 100±5 μm deep. The 1.35 mm³/min removal rate and the smooth machined surface with Ra=2.824 μm roughness depicting the high precise and efficient processing were achieved. The ablation characteristics of nanosecond laser process of Y-TZP ceramic were also studied. Based on the study, a reasonable design of the processing path for micromachining of a finer embedded step with 24±2 μm width (smaller than the 60 μm focused spot size) around the inner-wall of a 2×2 mm² cavity was developed. These results and discussion offer new possibilities in the manufacturing of bio-ceramic products by nanosecond laser with high processing quality and efficient.