Laser-assisted microscale deformation of stainless steels and ceramics

This work investigates deformation of stainless steel and ceramic specimens with a precision on the order of submicrometers by use of a pulsed laser beam as the energy source. Such a technique is useful, for example, in a process of removing distortions on magnetic head components for a better contact between the magnetic disk head and the hard disk surface. Experiments are conducted to study the bending behavior of stainless steel and ceramics due to laser irradiation. A pulsed Nd:YLF laser beam is used to scan over the specimen to create out-of-plane deformation. The amount of deformation from each laser scan is correlated with various laser and processing parameters. A theoretical model of the laser deformation process is presented based on thermo-elasticity/plasticity. The laser deformation process is explained as a result of the laser-induced non-uniform distribution of the residual strain. Numerical simulations are carried out to estimate the laser-induced temperature field, the residual stress field, and the amount of deformation of the specimen. These theoretical studies help to understand the complex phenomena involved in the pulsed laser deformation process.