Stainless steel is known as a corrosion-resistant material and this superior ability could be a desired property for a pinhole aperture operated in a corrosive environment and thereby be able to maintain both smoothness and a perfect circular shape in order to achieve precise beam alignment. Laser drilling has widely been preferred when placing holes into stainless steel due to its non-contact method of machining. In addition, this method is capable of performing delicate machining while inducing relatively low amounts of heat in the affected zone in comparison with other traditional machining techniques such as punching. Laser drilling is also beneficial for specimens having a thin thickness since manufacturing tolerances are minimal in this case. In this paper, we have attempted to produce holes of various diameters in 10 m thick stainless steel foil by using a femtosecond laser trepanned method. We have demonstrated these to be of perfect circular shape and adhering to low tolerance manufacturing by adjusting the beam parameters. In addition, holes with various diameters have been made by employing previously selected machining parameters and the viability of pinhole apertures fabricated by laser drilling have been evaluated.

Recently, the automatic laser-piercing has become a subject of growing research area in the hydroforming of car body and robotic fields. Generally, the laser-cutting with 6-DOF robot system has 3D error due to a gear backlash and inaccurate calibration method between sensor and cutting-tool. The objective of this article is to study the automatic laser-cutting for the micro-hole piercing of engine cradles. The development of redundant micro-control module and laser vision sensor contributes to the implementation of precise laser cutting. To obtain higher a performance of control module, the calibration algorithm between cutting-tool and laser sensor is required. The implementation of this methodology will be describe. The optimal path generation for a good quality of cutting section is also explained in detail. The experimental results demonstrate the successful operation in the automatic micro-hole piercing. It shows a validity of the micro-motion mechanism and robot‘s calibration algorithm in laser sensor.