Corrosion of Magnesium and Magnesium-Base Alloys

• Published in: ASM Handbook, Vol. 13B, Corrosion: Materials Vol. 13B; pp. 205 - 227
• Main Authors: Shaw, Barbara A, Wolfe, Ryan C
• Format: Reference
• Language: English
• Published: 01.01.2005
• ISBN: 0871707071; 9780871707079

Low density and high strength-to-weight ratio are usually the prime reasons for specifying the use of magnesium alloys in engineering designs. High stiffness-to-weight ratios, good castability, high thermal and electrical conductivity, and high damping capacity of magnesium alloys are also attractive properties. However, magnesium possesses a strong thermodynamic driving force for corrosion, and its surface film does not present a very protective kinetic barrier to corrosion. Despite these shortcomings, the interest in using magnesium alloys for a variety of applications is still high because of its weight advantage. Consumer uses of magnesium alloys include cases for personal electronics (laptop computers, cameras), luggage enclosures, handtools, frames for sunglasses, and even in space suits designed for use on Mars. The premier automotive use of magnesium is in the form of transmission casings; because these components are necessarily large structures, the weight savings realized with magnesium are substantial (20 to 25% over aluminum). Military uses for magnesium are extensive and include radar equipment, portable ground equipment, decoy flare ordnance, helicopter transmission and rotor housings, and in torpedoes.