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Arc voltage behavior in GMAW-P under different drop transfer modes

Praveen P., Kang M. J., Yarlagadda P. K. D. V.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 32, nr 2

196-202

EN

Purpose: Experimental measurements have been made to investigate meaning of the change in voltage for the pulse gas metal arc welding (GMAW-P) process operating under different drop transfer modes. 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 different drop transfer modes in GMAW-P. The investigation is based on the synchronization of welding signals and high speed camera to study the behaviour of voltage signal under different drop transfer modes. Findings: The results reveal that the welding arc is significantly affected by the molten droplet detachment. In fact, results indicate that sudden increase and drop in voltage just before and after the drop detachment can be used to characterize the voltage behaviour of different drop transfer mode in GMAW-P. Research limitations/implications: The results show that voltage signal carry rich information about different drop transfer occurring in GMAW-P. 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 GMAW-P is crucial for the appropriate selection of pulse welding parameters. As change in drop transfer mode results in poor weld quality in GMAW-P, so in order to estimate the working parameters and ensure stable GMAW-P understanding the voltage behaviour of different drop transfer modes in GMAW-P will be useful. However, in case of GMAW-P 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 different drop transfer modes for GMAW-P.

2

Detection of short circuit in pulse gas metal arc welding process

Yarlagadda P. K. D. V., Praveen P., Madasu V. K., Rhee S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

328-332

EN

Purpose: The paper discusses several methods of detecting occurrence of short circuit and short circuit severity in pulse gas metal arc welding process (GMAW-P). 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 the occurrence of short circuit and its severity in GMAW-P process. The investigation is based on the measurement of welding signals specifically current and voltage signals and their synchronization with high speed camera to investigate the short circuit phenomenon in GMAW-P process. Findings: The results reveal that short circuit can be detected using signal processing techniques and its severity can be predicted by using statistical models and artificial intelligence techniques in GMAW-P process. Research limitations/implications: Several factors are responsible for short circuit occurrence in GMAW-P process. The results show that voltage and current signal carry rich information about the metal transfer and especially short circuit occurrence in GMAW-P process. Hence it's possible to detect short circuit occurrence in GMAW-P process. Future work should concentrate on development of advance techniques to improve reliability of techniques mentioned in this paper for short circuit detection and prediction in GMAW-P process. Originality/value: For achieving atomization of the welding processes, implementation of real time monitoring of weld quality is essential. Specifically for GMAW-P process which is widely used for light weight metal which is widely gaining popularity in manufacturing industry. However, in case of GMAW-P process hardly any attempt is made to analyse techniques to detect and predict occurrence of short circuit. This paper analyses different techniques that can be employed for real time monitoring and prediction of short circuit and its severity in the GMAW-P process.

3

Characterization of dynamic behaviour of short circuit in pulsed Gas Metal Arc Welding of aluminium

Praveen P., Kang M. J., Yarlagadda K. D. V. P.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 14, nr 1-2

75--82

EN

Purpose: This paper studies dynamic characteristics of short circuit in the pulsed current gas metal arc welding (GMAW-P). 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 different short circuit conditions in GMAW-P. The investigation is based on the synchronization of welding signals and high speed camera to characterize different types of short circuit occurring in GMAW-P system. The behaviour of short circuit under the influence of different pulsing conditions is also investigated. Findings: It will be shown in the paper that short circuit in GMAW-P occurs in different forms which can be categorized depending upon time of short circuit and phase (peak or base time) of the pulse. Further investigation involves study of the dynamic behaviour of short circuit with variation of different pulsing parameters. Research limitations/implications: The results show that by varying the pulse parameters, behaviour of short circuit in GMAW-P is changed. The pulse parameters can be adjusted to avoid occurrence of short circuit in GMAW-P. Future work should concentrate on development of practical indices in terms of pulse welding parameters for quantitative estimation of short circuit occurrence and avoidance. Originality/value: Determination of proper working parameters with GMAW-P is crucial for the appropriate selection of pulse welding parameters. As short-circuiting is common between the welding electrode and the workpiece in GMAW-P, so in order to estimate the working parameters and ensure stable GMAW-P understanding dynamic behaviour of short circuit in GMAW-P will be useful. However, in case of aluminum hardly any attempt is made to analyse the dynamic behaviour of short circuit in GMAW-P. This paper analyses the short circuit phenomenon in GMAW-P and their behaviour with varying pulsing parameters.

4

Arc voltage behavior of one drop per pulse mode in GMAW-P

Praveen P., Kang M. J., Yarlagadda P. K. D. V.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

389--392

EN

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.