Laser-assisted microscale deformation of stainless steels and ceramics

Chie C. Poon Andrew C. Tam IBM Almaden Research Center 650 Harry Road San Jose, California 95120 Abstract. We investigate deformation of stainless steel and ceramic specimens with a precision of the order of tens of nanometers using a pulsed laser beam. Such a technique is useful, for example, in a process of removing distortions on magnetic head components to achieve 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 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 the result of the laser-induced nonuniform distribution of the compressive 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 us to understand the complex phenomena involved in the pulsed-laser deformation process. © 1998 Society of PhotoOptical Instrumentation Engineers. [S0091-3286(98)02710-X]