Experimental Investigation of the Laser Micro Drilling of Different Alloys by means of Nd:YAG Green Laser

Abstract Micro-machining have been subjected to an important develop in fabrication of components for informatics, electronic, and mobile telephone systems. Now a day they have been having a significant development in many strategic sectors like the mechanical, the chemical and the medical one. A lot of structures with dimension of few microns like micro pumps, micro motors, micro systems for the DNA analysis have been realized during the last ten years. The micromachining sector is potentially a strategic field in industry as actually occurs a big demand of micro components. For such a reason the following work has been carried on. The behaviour of different metals undergone to laser micro drilling varying the machining parameters has been studied in this work. The source used for the experiments is a Nd:YAG Q-Switched green laser. Materials machined are AISI 304, WC, Titanium, Inconel 718 and Brass. Machining parameters varied are: frequency and power of laser beam, focal lens length and thickness of materials. After the drilling the micro-holes obtained has been observed with a scanning electron microscope (SEM) with the aim of analyze their quality attributes. Quality attributes of the realized machining are: radial and vertical spatter, tapering and dimensions of the holes. Experimentation has been carried out using the method of design of experiment (DOE FACTORIAL). It is advantageous to realize micro-holes using a laser because this alternative technology allows to realize machining without contact between piece and tool. Such a machining permits also to reduce working time and to process materials very difficult to machine with other technologies.