LASERAP’6 Auteur correspondant : valentin@isim.ro 1 Statistical approach of Nd:YAG laser welding of aluminum matrix nanostructured composite material for MEMS technology Valentin Bîrdeanu 1 , Sorin SAVU 2 , Dorin Dehelean 1 , DănuŃ SAVU 1,2 1 ISIM Timisoara, Timisoara Romania 2 University of Craiova, Craiova, Romania Abstract MEMS technology requires special materials, e.g. composite materials with low weight and low friction coefficient and some of the components require joining in the assembly process. The paper presents the results of an experimental research using a statistical approach on pulsed laser welding of such composite materials (aluminum matrix with SiC carbide as reinforcement). The attention was focused on the influence of the laser parameters upon the dimensional range of the SiC carbides from the composite - a factor that determines the special mechanical characteristics of the material. A factorial experiment was designed to study the welding process parameters influence upon the dimensional range of SiC carbides distribution. Welding specimens were produced according to the designed experiment, the dimensional range of SiC carbides distribution was determined and a correlation to the process parameters, e.g. pulse power, pulse duration, etc. was established. For high heat inputs an increasing of the carbides had been observed. The carbides were growing up 80-100% and the nanostructure was affected and going to the micro-domain. Also future research directions for optimization are suggested. Keywords: MEMS, nanostructured composite materials, pulsed laser welding, factorial experiment 1. Introduction MEMS technology requires special materials, e.g. composite materials with low weight and low friction coefficient [1]. Discontinuous SiC reinforced CuAl matrix composite materials are used for manufacturing various MEMS components because they posses some advantages like almost zero thermal expansion coefficient, low density and satisfactory ductility. For the case that MEMS components imply mechanical moving parts, some of the components that can not be manufactured directly by sintering require further processing – cutting and / or joining. The further processing implies heat influence affecting the nano-structured material thus leading to a decrease of the special mechanical properties of the components. The experience comes from the elaboration of the composite material process. During the sintering for the elaboration the particles are increasing their dimension for more than 4 times [2,3,4]. Based on these facts an investigation on the effect of the laser melting (specific to the welding processes) on the nanostructure was performed. The experiment was completed with an appropriate statistical approach. 2. Material and Method To study the influence of the laser process parameters upon the dimensional range of the SiC carbides distribution from the composite material a complete factorial experiment [5,6] was designed. As base material a sintered 15%SiC CuAl matrix nano-structured composite shaped as a cylinder was used.