Various welding processes for joining aluminium alloy with steel: Effect of process parameters and observations–a review

The versatile aluminium alloys and steel are being used in automotive engines (exhaust systems), pressure vessels (flanges), turbine rotors, boilers (bonnet) and in many applications. The collective effect of these two metals created a revolution and are being utilized in most of the sectors wherein joining of these two dissimilar materials are always a major challenge faced by the manufacturers. Initially, the rivets were widely used for joining dissimilar materials owing to easy installation and flexibility, but the joint interlock fails and sudden ruptures occurred when exposed to higher load. Hence, numerous welding processes like metal inert gas welding, friction stir welding, friction stir spot welding, advanced laser welding, advanced cold metal transfer welding and hybrid welding techniques have been introduced in order to conquer the above problem because of residual stresses, cracks, distortion, and undercuts. Moreover, an appropriate standardization with controlled process inputs is still an uncertainty in joining the dissimilar materials. Hence, a detailed review on joining the dissimilar metals based on aluminium alloy and steel by various welding processes and influence of their parameters on the properties have been summarized in detail which would be a reference for manufacturing industries in the coming decades.

A Review on Evaluation of MIG Welding Process Parameter by using MOORAS Method

This review paper focus on Parametric optimization in Metal inert gas welding by using MOORAS method. MIG is arc welding process. Parameters optimization can be done by Multi-objective optimization on basis of ratio analysis and analytical Heriachy process. Ranking of alternatives determine by attributes weight or related importance given between attributes and on the values of the selected attributes,MOORA method is very fast and robust. It needs minimum Mathematical calculations and calculations time. Review paper endeavor process to illustrate problem by MOORAS method.

Intergranular corrosion susceptibility of 6061 aluminum alloy welded joints

The intergranular corrosion behavior of 6061 aluminum alloy welded joints produced by metal inert gas welding and friction stir welding was studied. The microstructure of the welded joints and the intergranular corrosion morphology of the cross-section were analyzed by optical microscopy. The results show that the most sensitive area of intergranular corrosion is the partially melted zone of the metal inert gas welding, and the maximum corrosion depth is about seven times that of the base metal, followed by the unmixed zone. The heat affected zone has the lowest sensitivity. Although the welding seam corroded seriously, general corrosion played a leading role. With the high heat input of metal inert gas welding, the sensitivity to intergranular corrosion in the partially melted zone increased significantly, while other zones had little change. For friction stir welding joints, the heat affected zone suffered from the most severe corrosion, and the nugget zone the least. However, the difference is not apparent. The susceptibility to intergranular corrosion of friction stir welding joints is weaker than that of metal inert gas welding joints but more severe than the base metal.

Effect of Double-Pulse Characteristics on Weld Bead Formation and Mechanical Properties in Metal Inert Gas Welding

Aluminum alloy has been widely used due to its excellent workability, and double-pulse metal inert gas welding (MIG) has become a popular technique in aluminum alloy welding. In this study, a cross-complementary test was performed to study the effect of double-pulse characteristics on weld bead formation and mechanical properties in MIG welding. The test was carried out on an AA6061 aluminum alloy using flat overlaying welding. After welding, the micro-metallographic structure and macro-mechanical performance of the weld bead were explored. The test results showed that the two methods of increasing the base current amplitude or the low-frequency of the current effectively enhanced the oscillation of the molten pool, refined the grain size of the fusion zone, and improved the mechanical properties of the weld. Additionally, by comparing the macroscopic photograph of the specimen and the corresponding welding parameters in the test, the formation characteristics of the bead’s fish-scale pattern in double-pulse MIG welding were found when appropriate welding parameters were adopted and weld bead formation was good. This test result provides a strong scientific basis for the selection of welding parameters in the actual promotion and application of double-pulse MIG welding.