Free Vibrational Characteristics of Dual Side Nd: YAG Laser Welded Stainless Steel 304 Joints Reinforced with Al <sub>2</sub> O <sub>3</sub> Micro Powder Particles

Abstract

<div class="section abstract"><div class="htmlview paragraph">Nd: YAG Laser Welding Process (LWP) is the most efficient method commonly used for the joining of different kinds of materials, whether it can be a sheet or plate. LWP in general, uses high power density, frequency and travel speed or feed rate as primary process parameters in order to perform a joining process across the metals. This paper investigates the effect of free vibrational characteristics for Stainless Steel 304 (SS 304) joints which are reinforced with Al<sub>2</sub>O<sub>3</sub> micro particles processed by dual side (welding performed on the top and bottom surface of sheets) Nd: YAG LWP. The inclusion of micro particles was inserted directly across the weld pool region, by fabricating drills with a constant gap between each drilled holes. Totally 12 samples were fabricated with different laser power, travel speed and by keeping the frequency level as constant for all the experiments. Vibration tests were performed on the fabricated samples made with and without incorporation of micro particles using accelerometer, data acquisition card, and the plots were obtained with the assist of DEWE software. The vibration equipment is used on the SS 304 joints in order to process the vibrational signals. Each sample has been tested with ten trials and the average values are drawn in order to reduce or minimize the measuring errors like (measuring error, fitting error, environmental impacts, etc.). The results revealed that vibrational characteristics are linked to factors like reinforcement of powders, selection of welding process and process parameters. It is also understood that the frequency and damping factor for a material can be varied with process parameters and inclusion of micro particles in the solidification process. Thus this paper will assist any designer to choose the process parameter ranges, reinforcement of powder particle methodology and their impact on the material behavior of fabricated joints.</div></div>