Laser Surface Engineering of Magnesium Alloys: A Review

Abstract

Magnesium (Mg) and its alloys are well known for their high specific strength and low density. However, widespread applications of Mg alloys in structural components are impeded by their insufficient wear and corrosion resistance. Various surface engineering approaches, including electrochemical processes (plating, conversion coatings, hydriding, and anodizing), gas-phase deposition (thermal spray, chemical vapor deposition, physical vapor deposition, diamond-like coatings, diffusion coatings, and ion implantation), and organic polymer coatings (painting and powder coating), have been used to improve the surface properties of Mg and its alloys. Recently, laser surface engineering approaches are attracting significant attention because of the wide range of possibilities in achieving the desired microstructural and compositional modifications through a range of laser-material interactions (surface melting, shock peening, and ablation). This article presents a review of various laser surface engineering approaches such as laser surface melting, laser surface alloying, laser surface cladding, laser composite surfacing, and laser shock peening used for surface modification of Mg alloys. The laser-material interactions, microstructural/compositional changes, and properties development (mostly corrosion and wear resistance) accompanied with each of these approaches are reviewed.

The Influence of the Asymmetric Arb Process on the Properties of Al-Mg-Al Multi-Layer Sheets / Wpływ Asymetrii W Procesie Arb Na Właściwości Wielowarstwowych Blach Al-Mg-Al

“…The appropriate value of asymmetry factor, a v , which is defined as the upper to lower roll rotational speed ratio, should cause additional shear stresses to occur in the strip being deformed, which will have the effect of activating the shear bands in the deformed strip. It should be noted that in the studies of the asymmetric sheet rolling process carried out so far the asymmetry factor did not exceed the value of 1.2 [14,15]. in studies [34][35][36], for rolling aluminium and magnesium sheets, a considerably greater asymmetry factor was employed, which in extreme cases ranged form 1.8 to 2.2.…”

“…The techniques used to produce Al cladding layers include: heating Mg-based components in contact with Al powder [8,9], electrodeposition [10], diffusion coating in molten salts [11,12], cold spray coupled with heat treatment [13], physical vapour deposition [14] and laser processing [15,16]. The above-mentioned methods provide an aluminium coating with a maximum thickness of ~10 μm and may result in a porous cladding surface, which might in some instances lead to a worsening of the corrosion resistance [17].…”

Development of Anti-Corrosion Processing on Magnesium Alloys

“…It has been recognized that laser surface engineering can produce surface layers with a fine microstructure that reduce the size of galvanic couples and expand the solid solution range of alloying elements [6,9]. Such factors can potentially improve surface performance of laser-treated metallic alloys.…”

“…However, Mg is a highly active element, which is susceptible to becoming corroded within its working condition, especially when Mg alloy serving as structural materials are immersed in corrosive media and combined with stress [5][6][7]. This limits the wide use of Mg alloys; therefore magnesium alloy anti-corrosion becomes an important issue.…”

Analysis of the Deformability of Two-Layer Materials AZ31/Eutectic / Analiza Możliwości Odkształcania Plastycznego Materiału Dwuwarstwowego AZ31/Eutektyka

“…Finally, the recycling of coated elements with such layers is not complicated because aluminium is the main alloying element of Mg alloys. The techniques used to produce Al-enriched layers include: heating Mg-based components in contact with Al powder [2][3][4][5], electrodeposition [6], diffusion coating in molten salts [7,8], cold spray coupled with heat treatment [9], physical vapour deposition [10], laser processing [11,12]. Depending on the employed fabrication process and its parameters, the microstructure of the resulted coating may be composed of two continuous layers of intermetallic phases: the outer layer-Al 3 Mg 2 and the inner layer-Mg 17 Al 12, or may have an eutectic structure of (Mg 17 Al 12, phase + solid solution of Al in Mg).…”