Metal transfer in the aluminum gas metal arc welding

Abstract

Among the aluminum welding processes, the GMAW (Gas Metal Arc Welding) process can be easily made automatic, has high productivity and great versatility regarding the type and thickness of material used in welding. The possibility of changing the transfer mode to adapt to different thickness, joint types, among other aspects, is another important and attractive feature. However, little is known about the transfer modes in aluminum GMAW process. For this reason, in this study an analysis of the metal transfer modes in the aluminum welding was made, and the objective was to generate maps that could identify the metal transfer modes and their regions in relation to the shielding gas and the wire diameter. The experimental procedure was the execution of weld on aluminum plate in a flat position with a constant voltage power source. The methodology used was laser Shadowgraphy combined with a high-speed movie camera. Therefore, it was possible to design the maps in which four metal transfer modes and their respective transition zones were determined. The maps also permit determination of the transition current zone between the globular and the spray mode, and modeling of the melting rate

Selection of parameters of pulsed current gas metal arc welding

“…For this reason, in spray or pulsed metal transfer it is more common to use helium contents less than 70% to combine the advantages of the hotter helium arc with the more constricted argon arc characteristics for droplet detachment. Fenaresi et al [55], in their investigations found that, change of shielding gas from pure argon to argon with 25% of helium, for welding of aluminum, there was an increase in the globular/spray transition current and frequency.…”

Advanced gas metal arc welding processes

“…It limits the highest current for globular transfer and the lowest for spray transfer and thus determines the working conditions of the process [66,67]. The GMAW-P process advances the concept of combined or hybrid metal transfer mode.…”

Influência dos teores de CO2 e O2 na corrente de transição globular-goticular utilizando misturas a base de argônio durante a soldagem GMAW de arame ER70S-6

“…Neste sentido é possível encontrar na literatura valores para esta corrente de transição globular-goticular (lembrando que também há a transição goticular-elongamento e elongamento-rotacional) para diferentes materiais e gases de composição binária [3][4][5][6]. Entretanto, uma avaliação mais atual se faz necessária com base na técnica de perfilografia (shadowgrafia) sincronizada [7], com uso de recursos computacionais avançados e com parâmetros de identificação do modo de transferência, que contemplem as recentes revisões do IIW [8][9][10] para definição destes modos de transferência metálica.…”

“…Vilarinho [2] fez uma recente revisão da classificação dos [3][4][5][6], onde se apresenta a tendência de aumento da corrente de transição e menor estabilidade da transferência com o aumento do teor de CO 2 na mistura a base de Ar para a soldagem de aços ao carbono. Estes artigos compreendem vários ensaios e procuram lidar com os aspectos fundamentais da transferência.…”