Surface Engineering Techniques and Applications

Magnesium and its alloys are a well-explored type of material with a multitude of applications ranging from biomedical prosthetics to non-biological tools such as automotive components. The use of magnesium and its alloys are highly desired for such applications mainly because magnesium is lightweight and possesses a high strength to weight ratio, which reduces the amount of energy required for the operation of an apparatus. In particular, the biomedical industry uses magnesium as orthopedic implants because of its strength properties that are similar to organic bone structures. Additionally, the highly corrosive or degrading nature of magnesium makes it suitable for degradable implants or medical devices. Cast magnesium alloys are also used as components in modern engines and automobiles, as magnesium's lightweight and high strength properties permit for faster automotive speeds, acceleration, and reduced energy consumption. Magnesium produces a quasi-passive hydroxide film that offers little to no inhibition of corrosion processes. Although the degree of film passivity can be increased through metallurgical techniques like alloying, the highly oxidizing nature of magnesium remains the single most important challenge to its widespread use. This chapter provides a detailed explanation of the most successful mechanisms used to control the corrosion of magnesium and its alloys and highlights the benefits and challenges for using them.