Predictions of temperature and stress fields around the hole perimeter of laser drilled micro-holes

Laser micro-hole drilling into stainless steel sheet was carried out and temperature and stress fields around the hole perimeter were predicted with a finite element method (FEM) model. The geometric features of the hole obtained experimentally were used in the simulations. Optical and scanning electron microscopy (SEM) were used to obtain micrographs of the top and bottom surfaces, and the cross-section of the hole. It was found that a high temperature gradient was developed in the region just below the surface. This in turn resulted in the development of high stress levels in this region.