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The aim of this work is to investigate the fundamentals of dislocation-particle interactions in a Mg-1%Mn-1%Nd (wt.%) (MN11) alloy in order to better understand the limited precipitation strengthening exhibited by this material. A combined approach including micromechanical testing, slip trace analysis, and high resolution transmission electron microscopy (TEM) is put in place to analyze the interaction between basal and non-basal dislocations with the Mg-Nd plate precipitates that are characteristic of the investigated alloy. It is shown that basal dislocations can easily shear the precipitates, both when their long axis lays parallel and perpendicular to the matrix c axis. This is attributed to the high coherency between the matrix and the particles, which is characterized in detail. It is additionally shown that pyramidal 〈c + a〉 dislocations, on the contrary, interact with precipitates both in the form of shearing along the precipitate pyramidal planes, as well as by Orowan looping. This study reveals that pyramidal dislocations are able to shear the plate precipitates along pyramidal planes when there is a good alignment between the slip plane of the incoming matrix dislocation and the outgoing precipitate pyramidal plane. Otherwise pyramidal dislocations sliding on matrix planes with small geometric compatibility with the precipitate pyramidal planes bypass these particles by an Orowan looping mechanism. "This project has received funding from the Clean Sky 2 Joint Undertaking (JU) under grant agreement No 755610. The JU receives support from the European Union's Horizon 2020 research and innovation programme and the Clean Sky 2 JU members other than the Union"

Magnesium is a biodegradable metal that has potential in orthopaedics. It has several advantages over other metallic materials because it is biocompatible and degradable now being used for biomedical applications, including elimination of stress shielding effects, enhancing degradation properties and enhancing biocompatibility concern in vivo, eliminating the second surgery for implant removal. Bioabsorbable magnesium (Mg) and related alloys have been limited in their usage because of its lower corrosion resistance. Surface alteration and functionality, in addition to basic alloying, is an important technique to deal with Mg and its alloys' reduced corrosion resistance. Magnesium's rapid depreciation however is a double-edged sword because it's critical to match bone renewal to material corrosion. As a result, calcium phosphate coatings have been proposed as a way to slow down corrosion. There are various possible calcium phosphate phases and their coating methods and can give a few distinct properties to various applications. Despite magnesium's lower melting point and greater reactivity, calcium phosphate coatings require precise settings to be effective. Because of their toxicity, non-biodegradability, and much higher cost, the recently used inorganic conversion coatings are less appealing and their application is limited. Conversion coatings are a viable alternative technology that is based on a cost- effective, environmentally friendly, and biodegradable organic component. Surface chelating functional groups in these compounds allow them to link with the magnesium/surface hydroxide layer while also providing anchoring groups for the polymer topcoat. Nanoreservoirs with multilayer inhibitors for active self-healing corrosion resistance thrive in this environment. This study examines the organic conversion coatings for Mg and its alloys in depth.

This paper deals with welding AZ 31Mg alloy by FSW (Friction Stir Welding) technology. Welds were fabricated with new equipment supplied from China for VUZ-PI Bratislava (Welding Research Institute — Industrial Institute). Welding parameters and conditions were proposed and tested. Joint quality was assessed by optical microscopy and microhardness measurements. The fabricated joints were sound, apart from minor inhomogeneities (cracks). It is considered that after certain adaptations of the welding parameters, and perhaps also of the welding tool, that this equipment will be capable of producing welded joints of excellent quality that can compete with any fusion welding technologies, including concentrated power sources.

The ballistic impact resistance of lightweight magnesium alloys is an eye-catching material for the military and aerospace industries, which can decrease the cost of a project and the fuel consumption. The shockwave mitigation ability of a magnesium alloy is 100 times stronger than an aluminum alloy; nonetheless, ballistic impact resistance has still not been achieved against blunt and API projectiles. The major obstacles are the low hardness, low mechanical strength, basal texture and strain hardening ability under loading along the normal direction of the sheet. The high yield strength and ultimate strength can be achieved for a specific loading condition (tensile or compression) by adjusting the texture in magnesium alloys. The projectile impact along the normal direction in a strong basal-textured magnesium alloy can only produce a slip-induced deformation or minor twinning activity. Here, we propose a practical technique that can be valuable for altering the texture from c-axes//ND to c-axes//ED or TD, and can produce high strain hardening and high strength through a twinning and de-twinning activity. Subsequently, it can improve the ballistic impact resistance of magnesium alloys. The effect of the technique on the evolution of the microstructure and possible anticipated deformation mechanisms after ballistic impact is proposed and discussed.