Advances in laser beam shaping technologies are being studied and are considered beneficial in many aspects of dissimilar metal joining, which include reducing intermetallic compounds (IMCs), optimizing weld pool profiles, and controlling porosity and spatters. This paper utilizes a coaxial ring and core dual beam laser and aims to study the impact of the power ratios between core and ring beams on the weldability of 1100 aluminum alloy to hilumin (steel). High-resolution electron microscopy was performed in the cross sections of the weld pools to quantify the melt pool composition and subsequent IMC formation and weld defects (cracking and cavitation). Lap-shear mechanical testing and electrical resistivity testing were also carried out. Results showed that the optimal power ratio for lap-shear strength was 0.4 (intermediate core and ring) due to the reduction in the Fe-rich liquid into the upper weld region. As a result, this produced a smaller interface between the Fe-rich region and Al, thus reducing the formation of the most detrimental IMC (e.g., Fe2Al5). Conversely, a power ratio of 0.2 (core-dominant) was found beneficial for reducing electrical resistance due to a reduced total IMC volume.

Commercially pure aluminium is employed in several industrial applications. On some applications, the surface of this material needs to be functionalised. Laser surface texturing is a powerful tool to functionalise aluminium and aluminium alloy surfaces. However, the corrosion resistance of the laser textured aluminium alloy can be modified, and this has rarely been investigated in the literature. Consequently, the corrosion resistance of the laser textured commercially pure aluminium in saltwater was evaluated using several electrochemical techniques: asymmetric electrochemical noise, potentiodynamic polarisation curve and electrochemical impedance spectroscopy. Although the non-laser surface textured samples possessed higher kinetic corrosion resistance in the first hours of immersion, the corrosion mechanism (process group of the corrosion) was found to be more unstable than the laser textured specimens. The oxidised layer of the textured samples was also nobler than the native passive film.

In the last two decades, the automotive industry has been facing demands to reduce fuel consumption and to meet CO₂ emissions through applications of lightweight materials. Therefore, aluminium alloys have replaced substantial amounts of steel; and they are receiving significant attention to achieve greenhouse emission targets. However, a critical factor in applications of advanced aluminium in automotive Body in White (BIW) designs depends on availability of cost effective and high performance joining processes. Currently, a Self-Pierce Riveting (SPR) process is extensively used for aluminium BIW sheet metal parts joining which is expensive, additionally increase the weight of the vehicle and cause inefficiency in manufacturing operations. As aluminium alloys are difficult to weld by conventional technologies such as electrical resistance spot welding, MIG arc welding etc., various joining technologies had proposed to weld aluminium alloys and dissimilar alloys over the years. Often, these technologies restrict design flexibility and are expensive for mass production. In this context, Remote Laser Welding (RLW) has gained popularity because of its distinct advantages such as design flexibility, production speed, material and cost savings. This paper provides a critical review of challenges and opportunities for application of RLW to dissimilar metal welding of steel to aluminium. Next steps of research and development are also highlighted.