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The high specific strength makes magnesium alloys have a wide range of applications in aerospace, military, automotive, marine and construction industries. However, its poor corrosion resistance and weldability have limited its development and application. Friction stir welding (FSW) can effectively avoid the defects of fusion welding. However, the microstructure, mechanical properties and corrosion behavior of FSW joints in magnesium alloys vary among different regions. The purpose of this paper is to review the corrosion of magnesium alloy FSW joints, and to summarize the protection technology of welded joints.

The corrosion of magnesium alloy FSW joints includes electrochemical corrosion and stress corrosion. This paper summarizes corrosion protection techniques for magnesium alloys FSW joints, focusing on composition, microstructure changes and surface treatment methods.

Currently, this research is mainly focused on enhancing the corrosion resistance of magnesium alloy FSW joints by changing compositions, structural modifications and surface coating technologies. Refinement of the grains can be achieved by adjusting welding process parameters, which in turn minimizes the effects of the second phase on the alloy’s corrosion resistance.

This paper presents a comprehensive review on the corrosion and protection of magnesium alloys FSW joints, covering the latest research advancements and practical applications. It aims to equip researchers with a better insight into the field and inspire new studies on this topic.

MAGNESIUM, because of its low density, has obvious possibilities as an aircraft structural material. The useful magnesium alloys have densities in the range 1·76 to 1·83, compared with the aluminium alloys range of about 2·5 to 2·8. The melting point of magnesium is 650 deg. C., almost identical with that of aluminium (660 deg. C.), so that generally the alloys of each of these base elements have applications in much the same temperature band.

THE application of magnesium‐rich alloys to the numerous purposes of the aero‐plane industry continuously increases as a result of the important improvements effected in the production of pure magnesium and in the manufacture and treatment of magnesium‐rich alloys. Their low specific weight of 1·8 makes these magnesium alloys the lightest metallic constructional materials in existence and their various working treatments, including casting, pressing, rolling and machining (permitting exceptionally high cutting speeds), are considerably cheaper than those of the heavy metals. Numerous English firms (such as the Birmingham Aluminium Casting Co., Ltd., Smethwick, Birmingham; Magnesium Castings and Products, Ltd., Buckingham; Sterling Metals, Ltd., Coventry; Smith's Stamping Works, (Coventry) Ltd., etc.) manufacture machined parts of many descriptions for the aeronautical industry.

ONE of the primary considerations in the design of high performance aircraft is the attainment of a high power/weight ratio for the unloaded machine, while at the same time ensuring complete reliability under the most exacting service conditions.

The purpose of the present paper is to develop a new technology for producing magnesium alloy twin-rib aircraft brackets by the forging method.

An overall description of magnesium alloys is given, with particular emphasis placed on magnesium wrought alloys that are used in the aircraft industry. Methods for producing ribbed brackets are discussed and the location of these parts in aircraft structure is described. The forging process for producing AZ31 magnesium alloy twin-rib brackets was modelled numerically, and selected results of the simulations performed are presented. The simulation results were then verified under laboratory conditions using a three-slide forging press equipped with three movable working tools. It was assumed that the use of this machine would allow for obtaining twin-rib aircraft brackets with improved both functional and strength properties compared to the production methods used so far.

The results demonstrate that the method developed by the present authors permits the production of twin-rib brackets. Positive theoretical results and preliminary experimental results prove that it is justified that the research on magnesium alloys used in the aircraft industry be continued.

The production of twin-rib aircraft brackets from magnesium alloys by the technology developed by the present authors would lead to enhanced product quality with simultaneous reduction in production costs (reduced labour costs and material consumption as well as increased process efficiency). At present, magnesium alloy aircraft parts, mainly obtained from semi-finished products imported to Poland, are produced by casting and machining methods. They exhibit, however, much worse properties than elements produced by metal forming methods. In addition to that, the application of machining in the production of these part leads to higher production costs.

The originality of this study stems from the presentation of an innovative metal forming technology for producing twin-rib brackets. This method is unique on a global scale, and its basic assumptions have been granted patent protection. Also, the originality of the study stems from the fact that brackets are made from magnesium alloys, as these light metals are considered the future of structural materials used in the aircraft industry. Given the above, the research on developing the technology for producing parts made from these alloys using a three-slide press is justified.

The purpose of this paper is to investigate the electrodeposition of copper coatings directly onto AZ31 magnesium alloy, considered as a substrate of electroplating nickel. The additive, pH, complexing agent, current density, time, and temperature of electrolytic bath were studied to understand electrodepositing copper coating on AZ31 magnesium alloy.

Electrodeposition of copper was carried out in an aqueous solution containing copper hydroxide, citrate, and fluorine ion, which avoids the replacement or corrosion of the magnesium alloy. The morphology, structure, and interface of the electrodeposited copper coating were investigated by a scanning electron microscope (SEM).

The copper coating was dense, and there was good adhesion of the copper coating on the AZ31 magnesium alloy. This suggests that successful deposition of copper using an electroplating process could decrease the cost of coating AZ31 magnesium alloy.

This paper will be helpful for the development of coating on magnesium alloy using electroplating processes.

Copper hydroxide and citrate were the main compositions of the electrolyte, combined with sodium poly dipropyl (SP) and polyethylene glycol (PEG) as brightening agents and can be used to electrodeposit copper directly onto AZ31 magnesium alloy.

THE procedures incidental to the use of magnesium alloys are not unduly difficult or complicated, but until recently engineers in this country (U.S.A.) have been prone to use and treat magnesium alloys exactly like aluminium, with the result that in some cases trouble was encountered and magnesium was given the reputation of not being suitable for that particular application. These difficulties were caused both by lack of interest on the part of the aircraft industry and by a lack of sufficient knowledge on the subject. The aircraft industry is now showing great interest in magnesium alloys, and the magnesium industry is devoting a great deal of time and effort on new alloys, surface protection, and methods of fabrication.

This paper aims to investigate the corrosion evolution process of AZ91 magnesium alloy in 3.5 wt.% NaCl solution under different stresses by using in situ methods, thereby evaluate the influence of stress on the corrosion sensitivity of AZ91 magnesium alloy, and discuss the potential mechanism.

A four-point bending method was used to apply different loads to the magnesium alloy samples, a charge coupled device camera and electrochemical impedance spectroscopy test being used for in situ study. Scanning electron microscopy and X-ray diffraction (XRD) analysis were performed for corrosion product and morphology characteristics.

The observation results show that the corrosion of AZ91 magnesium alloy becomes more and more serious with the increase in the stress and generated many corrosion products. Originally, corrosion products prevented alloy matrix from contacting the corrosive medium. However, the increase in the stress facilitated the emergence of the corrosion holes in the corrosion products, which provided the microscopic channels for corrosive solution to attack the Mg alloy matrix, and accelerated the corrosion of the magnesium alloy, resulting in a lot of corrosion pits on the magnesium alloy surface under the corrosion product layer.

The evolution information of corrosion process is crucial to explore the mechanism of corrosion. Currently, most researches about corrosion of magnesium alloy used traditional testing techniques to obtain corrosion information, lacking the direct tracking and monitoring of the corrosion evolution process. Hence, this paper focuses on in situ corrosion study of AZ91 magnesium alloy. The technology with spatial resolution capability observed the changes in magnesium alloy surface at different times in the corrosion process in situ. Meanwhile, the in situ electrochemical technology was used to monitor the changes in micro-electrochemical signals during the corrosion process of magnesium alloy under different stresses.

Surface coatings are applied to magnesium alloys against the destructive attack of salt spray or marine exposure, industrial atmospheres, etc. Most of these alloys contain aluminium and minute amounts of impurities which reduce the corrosion resistance of magnesium, whereas manganese improves its corrosion resistance. This article describes the various methods of treatment and painting used to preserve magnesium alloys, extensively used nowadays in castings where lightness is essential.

The purpose of this paper is to examine the performance of cold-sprayed Zn15Al alloy coating whether it is capable of protecting magnesium alloy from corrosion, and to compare it with arc-sprayed Zn15Al alloy coating.

In this paper, Zn15Al alloy coating was prepared with CS-6000 cold spraying system and HDX-800 arc-sprayed system. Corrosion behaviors of the two kinds of coatings were examined with potentiodynamic polarization curves methods combined with SEM, EDS, XRD, etc.

Corrosion behavior of cold-sprayed Zn15Al alloy coating is superior to arc-sprayed Zn15Al alloy coating. The bonding strength and density of cold-sprayed Zn15Al alloy coating is much higher than that of arc-sprayed Zn15Al alloy coating. The cold-sprayed coating has a dense structure which separate magnesium from corrosion medium completely. The samples behave as Zn15Al instead of AZ91D alloy. The coating has a low probability of pitting corrosion comparing with cold sprayed Al coating through potentiodynamic polarization curve.

Cold-sprayed Zn15Al coating can be used to improve the anticorrosion performance of magnesium significantly and low down the risk of pitting corrosion of coating.

Cold-sprayed Zn15Al coating is an environmentally friendly anticorrosion method for light alloy, which is also the most effective way among thermal spray, chemical vapor deposition, sol–gel, plating and anodizing or microarc oxidation.

The present paper used cold spray method to deposit Zn15Al coating, which has an overwhelming performance both in physical and anticorrosion to traditional thermal spray method.