Corrosion and Surface Treatment of Magnesium Alloys

Abstract

The need for fuel efficiency and increased performance in transportation systems continually places new demands on the materials used. The design criteria which automobile and aerospace industries are primarily concerned with are density, strength, stiffness, and corrosion resistance. Low-density materials may reduce fuel costs, increase range, and allow larger payloads. High strength and stiffness are necessary for adequate performance and safety characteristics, while corrosion resistance helps to ensure that design lifetime is achieved.Magnesium is the th most abundant element on the earth making up approximately . % by mass of the earth s crust and . % by mass of the oceans [ ]. Other advantages of magnesium alloys have played an important role in a broad variety of structural applications in the automobile, aerospace, electronics, and consumer products industries. Magnesium has specific high strength to weight ratio, and it is % lighter than aluminium and % lighter than iron. Typical magnesium alloys weigh ~ % less than their aluminium counterparts at equal stiffness. Magnesium also has high thermal conductivity, good electromagnetic shielding characteristics, good ductility, excellent castability and better damping characteristics than aluminum, and Mg is easily recycled. The main use of magnesium by far is as an alloying addition to aluminum alloys. Other major uses of magnesium include desulphurization of steel and the production of ductile iron. "s a structural material, it can be used in aerospace components, automobile and computer parts, mobile phones and sporting goods. Magnesium for structural applications is processed into castings die, sand, permanent mold and investment , extrusions, forgings, impact extrusions and flat rolled products. Die castings account for % of the castings shipped. Magnesium can be joined by riveting, or any of the commonly used welding methods [ ].With the dramatically increased emphasis on weight reduction, magnesium is receiving a lot of attention as a material for use in the next generation automobiles. This is due to limited fossil

Effect of Heat Treatment on the Corrosion Behavior of Mg-10Gd Alloy in 0.5% NaCl Solution

“…In fact, generally Mg alloys could be classified into two main groups: (1) those containing Al as the primary alloying element. To increase the tensile yield strength and the castability of Mg alloys by forming the intermetallic phase Mg 17 Al 12 (Victoria-Hernandez et al, 2013); and (2) those free of Al and containing small additions of Zr for the purpose of grain refinement (Hu et al, 2014), besides forming intermetallics with Fe and Ni in the melt (Emley, 1966). Additions of Zn are also important as Al in the magnesium alloys to increase strengthening and castability (Meza-García, 2010).…”

In Vivo Response of Growth Plate to Biodegradable Mg-Ca-Zn Alloys Depending on the Surface Modification

“…The main drawback of these materials is the formation of hydrogen gas and aqueous solutions during their rapid degradation [3,7,8,9], which leads to further implant degradation [10,11]. Accordingly, various attempts have been made to produce Mg alloys and modify their surface to slow the degradation rate and regulate the by-product formation [2,7,8,12,13,14]. In this process, some Mg alloys even contain aluminum or heavy rare earth elements [1,10,12,14,15].…”

The Influence of Friction Stir Welding of Dissimilar AZ31 and AZ91 Magnesium Alloys on the Microstructure and Tensile Properties

“…The need for lightweight and increased performance in automobile industry has triggered the research on light metal, especially on magnesium (Mg) and its alloys because magnesium alloy are lightest metallic material with high specific strength [1], low density reduces fuel cost, high specific strength and high specific rigidity [2], good damping properties [3], stiffness, high thermal conductivity, good ductility, good cast ability [4]. The density of magnesium is about 35% of aluminium and 75% of that of iron; magnesium becomes an excellent potential as a structural material.…”