Corrosion And Corrosion Prevention Of Low Density Metals And Alloys

Magnesium (Mg) alloys have low corrosion resistance and exhibit unusual corrosion behavior in aqueous environments. Because of this unique corrosion performance, some special corrosion prevention techniques have to be employed for Mg alloys in their applications. This chapter briefly summarizes the corrosion characteristics of Mg alloys, and also presents a strategy and methodologies to mitigate the corrosion damage of Mg alloys in applications.

Aggregated Book

Aggregated Book

Corrosion, Volume 1: Metal/Environment Reactions is concerned with the subject of corrosion, with emphasis on the control of the environmental interactions of metals and alloys used as materials of construction. Corrosion is treated as a synthesis of corrosion science and corrosion engineering. This volume is comprised of nine chapters; the first of which provides an overview of the principles of corrosion and oxidation, with emphasis on the electrochemical mechanism of corrosion and how the kinetics of cathodic and anodic partial reactions control the rate of overall corrosion reaction. Attention then turns to the effects of environmental factors such as concentration, velocity, and temperature based on the assumption that either the anodic or cathodic reaction, but not both, is rate-controlling. The corrosion of ferrous and non-ferrous metals and alloys, as well as rarer and noble metals, is considered. The reader is also introduced to high-temperature corrosion and mechanical factors that affect corrosion. This book concludes with topics of electrochemistry and metallurgy relevant to corrosion, including the nature of the electrified interface between the metal and the solution; charge transfer across the interface under equilibrium and non-equilibrium conditions; overpotential and the rate of an electrode reaction; and the hydrogen evolution reaction and hydrogen absorption by ferrous alloys. This book will be of value to students as well as workers and engineers in the field of corrosion.

Plating on Mg alloys has proved difficult due to their high susceptibility to the degradation reactions such as galvanic corrosion in the plating processes. In this chapter, surface conditioning, activation, electroless- or electroplating methods are discussed from viewpoints of corrosion engineering. Degradation reactions of the Mg substrate in each plating stage are considered to figure out how to suppress degradation of substrate and to achieve uniform deposition of a plating layer. Building up an interface between the substrate and the plating layer is also an important subject to establish enough adhesion strength of the plating layer and low defect density to prohibit corrosion progress of the substrate. Al coating plating on Mg alloys electrodeposited from an ionic liquid bath is also introduced to provide coatings with less-galvanic coupling property with a less-noble Mg substrate.

This book introduces corrosion mechanisms and protection technologies for metallic and non-metallic materials. A focus lies on the protection of high-tech materials with applications in space and environments exposed to unclear radiation and biological hazards. The determination, measurement and control of different corrosion mechanisms are discussed in detail. Combining theories with case studies, it is an essential reference for material scientists and engineers.

Comprehensive approach to scientific principles and methods that underlie the cause, detection, measurement and prevention of many metal corrosion problems engineering practices.