Ultrafast laser selective phase removal for surface modification of nanocomposite materials

Ultrafast laser processing of zirconia/alumina nanocomposite ceramics, the current gold standard material for ceramic bearing components in orthopedics, was investigated. Instead considering substrate as a homogeneous material, commonly assumed micromachining, damage behavior different phases around ablation threshold upon ultrafast irradiation Under appropriate experimental conditions, zirconia phase selectively ablated while alumina remained intact. The origin this selective and its relationship with band gaps were discussed. Due to nonlinear absorption mechanisms under irradiation, phase, gap 5.8 eV, can absorb more energy than which has larger 8.8 eV. negligible heat diffusion length ensures that absorbed remains confined individual phases, leading given fluence. Based on observation, an removal method be used modify surface composition materials consisting proposed.