Gas Metal arc Pulse Welding with Alternating Current for Lightweight Materials

Abstract

So-called heat-reduced arc welding processes dominate the joining technology in the automotive sector today. They offer the advantage to reduce deformation of thin walled plates. Also, metallurgy and material properties are affected decisively. Based on the present state of the art in power-controlled gas metal arc welding (GMAW) this paper present the developing of a welding process, that allows a quasi-decoupling of the energy input between filler metal and base material. This is being realized by a polarity reversal. In conjunction with pulse control and the specific adjustment of the pulse a significant improvement of the arc stability can be achieved. This applies particularly to non-ferrous materials tending to concentrate oxygen on its surface like aluminum, magnesium and their combinations, respectively. Especially it is possible to control the deposition rate, welding formation and bonding conditions between base material and filler metal. Furthermore spatter can be reduced and manufacturing time can be saved. The present investigation includes the comparison between various modern GMAW processes, such as ColdMIG®, CMT® and short arc, with the pulsed GMAW using alternating current (AC) for welding aluminum. Thereby, mainly the penetration depending on the heat input is taken into account. It can be noted that the AC pulsed GMAW process produces weld seams of the same quality as well-known processes in matters of height and width of the joint. The generated welds have low notches at the edge of the seam and a uniform weld scaling. Visual imperfections on the surface have not been detected.

Physical and mechanical properties of semi-automatic MIG welding of AA5083H116 materials

“…Hasil pengelasan MIG bahan 5083H111 yang dilakukan oleh Borrego, et al [4] struktur mikro dapat diperhalus dan sifatsifat mekanik dapat ditingkatkan dengan melakukan friction stir processing. Proses pengelasan MIG dengan bentuk gelombang arus las busur pulsa (pulsed arc) memberikan keuntungan tanpa spatter dengan masukan panas lebih kecil dibandingkan dengan arus las busur pulsa konvensional Dan mengurangi resiko peretakan panas (hot cracking) [5]. Las busur pulsa konvensional dimaksudkan belum ditambah alat pengatur arus sehingga mengganggu sumber tenaga menjadikan busurnya tidak stabil.…”

Investigation of the Microstructures and Mechanical Properties of Thin 5083 Aluminum Alloy Plates Welded by Double Pulse Gmaw Method

“…This situation is an important factor to use energy efficiently without any decrease in workforce and protect the environment. As a result, different materials and material combinations are used to carry out all requirements in machines and constructions (Brumm & Bürkner, 2015). Light engineering alloys are used significantly for energy conservation especially in aerospace, automotive and marine industries.…”

“…Considering this situation, the welding of thin aluminum alloy plates/profiles became a necessity to increase the energy efficiency of many machines. The efficiency and reproducibility of the welded joints in these materials have a profound effect on the quality of manufacturing processes and the economic feasibility (Brumm & Bürkner, 2015). However, there are important problems that restrict the welding of aluminum alloys such as solidification cracking, porosity formation, the perforation of thin plate during welding, oxide layer at the surface of alloy and distortion and internal stresses formation in weld seam due to the high thermal expansion coefficient of the material (Gungor et al, 2014), , (Zhu et al, 2015).…”

“…The inability in precise control of penetration during welding causes the perforation of plates or changing in the forms (shapes) of welding grooves (Feng et al, 2009). Furthermore, the solidification of aluminum alloys occurs rapidly due to high thermal conductivity and relatively low melting temperatures of material and thus, there is no time left for gas bubbles to escape from welding seam (Brumm & Bürkner, 2015). The thin oxide layer (Al2O3) at the surface of alloy that has higher melting point than aluminum, should be also removed from the welding area with a suitable welding method after mechanical and chemical cleaning.…”

“…The thin oxide layer (Al2O3) at the surface of alloy that has higher melting point than aluminum, should be also removed from the welding area with a suitable welding method after mechanical and chemical cleaning. Due to these situations in the welding of aluminum alloys, the required thermal input for material (although the melting point of aluminum is lower than steel) is almost the same with thermal input in steel welding (Brumm & Bürkner, 2015). Therefore, the applied thermal input in the welding of aluminum alloys should be adjusted and controlled precisely to obtain a proper and high strength joint.…”