Experimental Investigation of Laser Welding Process in Butt-Joint Configurations

Abstract

This paper presents an experimental investigation of laser welding low carbon galvanized steel in butt-joint configurations. The experimental work is focused on the effects of various laser welding parameters on the welds quality. The investigations are based on a structured experimental design using the Taguchi method. Welding experiments are conducted using a 3 kW Nd:YAG laser source. The selected laser welding parameters (laser power, welding speed, laser fiber diameter, gap between sheets and sheet thickness) are combined and used to evaluate the variation of four weld quality attributes (bead width, penetration depth, underfill and hardness) and to identify the possible relationship between welding parameters and weld physical and geometrical attributes. The effects of these parameters are studied using ANOVA to find their contributions to the variation of different weld characteristics. Plots of the main effects and the interaction effects are also used to understand the influence of the welding parameters. The results reveal that all welding parameters are relevant to bead width (BDW) and depth of penetration (DOP) with a relative predominance of laser power and welding speed. The effect of laser fiber diameter on penetration depth is insignificant. Typical gap-dependent weld shapes show that a small gap results in a narrower and deeper weld. Due to the standard sheared edge, an underfill between 5% and 10% occurs for no-gap experiments. The resulting hardness values are relatively similar for all the experimental tests.

ANN Based Predictive Modelling of Weld Shape and Dimensions in Laser Welding of Galvanized Steel in Butt Joint Configurations

“…The factors and levels used to generate the data for training and validation are presented in Table 1. These factors and levels are chosen based on structured experimental investigations [17] and exhaustive 3D modelling and simulation [18].…”

Gap and Force Adjustment during Laser Beam Welding by Means of a Closed-Loop Control Utilizing Fixture-Integrated Sensors and Actuators

“…The welding process leads to an inhomogeneous and transient temperature distribution, resulting in residual stresses that can cause deformation [12]. Distortion is based on plastic deformation and induces a displacement of the parts to be welded, which affects the energy deposition in the workpiece [13] and causes changes in weld-seam geometry and penetration depth in particular [14]. The process is interrupted when the displacement reaches a critical gap size, i.e., the melt pool is no longer able to bridge the gap between the parts to be welded, or the laser beam is transmitted through the gap in the case of butt welds [15].…”

Effect of thermal behavior on the grain morphology and dimension of 80-mm-thick Ti6Al4V plates joined by laser melting deposition

“…In contrast to conventional processing method such as multi-layer and multi-pass welding, Laser Welding with Metal Powder (LWMP) has unique and obvious advantages including a high-intensity heat source, low heat distortion, small heat affected area, fast processing efficiency and good metallurgical bonding [4][5][6][7][8][9][10]. Most of previous research on LWMP processes mainly concentrates on the influence of the filler material on the microstructure and the mechanical properties of the joint [11][12][13][14][15][16]. However, LWMP is only applied to join thin plates with thick of 1~5mm at present.…”