© Copyright by International OCSCO World Press. All rights reserved. 2006 VOLUME 17 ISSUE 1-2 July-August 2006 Short paper 389 of Achievements in Materials and Manufacturing Engineering of Achievements in Materials and Manufacturing Engineering Arc voltage behavior of one drop per pulse mode in GMAW-P P. Praveen a, *, M.J. Kang a,b,c , P.K.D.V. Yarlagadda b a School of Engineering Systems, Queensland University of Technology, 2 George Street, Brisbane, Qld 4001, Australia b Production Technology Center, Korea Institute of Industrial Technology, 994-32, Dongchun-dong, Yeonsu-gu Incheon, 406-130, South Korea c Working as a research fellow in School of Engineering Systems, QUT, Australia * Corresponding author: E-mail address: p.posinaseeti@qut.edu.au Received 15.03.2006; accepted in revised form 30.04.2006 Manufacturing and processing AbstrAct Purpose: Experimental measurements have been made to investigate the meaning of the change in voltage for the pulse gas metal arc welding process through one drop per pulse mode (ODPP). Design/methodology/approach: Welding experiments with different values of pulsing parameter and simultaneous recording of high speed camera pictures and welding signals (such as current and voltage) were used to identify ODPP drop transfer mode in pulse gas metal arc welding. The investigation is based on the synchronization of welding signals and high speed camera to study the behaviour of voltage signal under ODPP. Findings: The results reveal that the welding arc is significantly affected by the molten droplet detachment. In fact, sudden increase and drop in voltage just before and after the drop detachment characterizes the voltage behaviour of ODPP drop transfer mode in pulse gas metal arc welding. Research limitations/implications: The results show that voltage signal carry rich information about different drop transfer occurring in pulse gas metal arc welding. Hence it’s possible to detect different drop transfer modes. Future work should concentrate on development of filters for detection of different drop transfer modes. Originality/value: Determination of drop transfer mode with pulse gas metal arc welding is crucial for the appropriate selection of pulse welding parameters. As change in drop transfer mode results in poor weld quality in pulse gas metal arc welding, so in order to estimate the working parameters and ensure stable pulse gas metal arc welding understanding the voltage behaviour of different drop transfer modes in pulse gas metal arc welding will be useful. However, in case of pulse gas metal arc welding hardly any attempt is made to analyse the behaviour of voltage signal for different drop transfer modes. This paper analyses the voltage signal behaviour of ODPP mode for pulse gas metal arc welding. ODPP mode widely used to achieve best quality weld. Keywords: Welding; Arc voltage; One drop per pulse 1. Introduction Pulse gas metal arc welding (GMAW-P) is widely used arc welding process for thin sheet metal joining especially with aluminium [1-5]. In GMAW-P, the welding current is alternatively and periodically varied between background (or base) and peak (or pulse) values as shown in Figure 1. The main setting parameters which influence weld quality or wire melting are background current I b , peak current I p , background time T b , peak time T p and wire feed rate. In order to obtain proper weld quality, optimal values of these parameters should be set which ensures drop transfer mode. Several researchers studied the various aspects of GMAW-P [6]. Quintino et al. [7] and Ueguri et al. [8] found that peak 1. Introduction