The Metallurgy of Anodizing Aluminum: Connecting Science to Practice
Author: Jude Mary Runge
Publisher: Springer International Publishing AG (2018)
Review by Joseph C. Benedyk, Editor
As a recognized international expert on nonferrous metallurgy, Jude Mary Runge, Ph.D., has devoted her career of some 30 years to surface science and most particularly to the metallurgy of anodized aluminum and aluminum alloys. She has worked with many companies to improve their anodizing practices, most notably as the inventor and developer of the CompCote® process (involving a high performance anodized aluminum-polymer coating) and more recently working with Apple, Inc. on their anodized aluminum products. As an active member of the Aluminum Anodizers Council (AAC), teaching about the metallurgy of anodized aluminum at their anodizing workshops, and having lectured and presented papers internationally on her research, her book has been anticipated by many anodizing professionals.
For anodizing specialists schooled in the various editions of what has been considered their “bible” — The Technology of Anodizing Aluminum by Dr. Arthur W. Brace, which details the practice of anodizing — Dr. Runge’s book adds a metallurgical outlook to the subject. The Metallurgy of Anodizing Aluminum describes to readers the connection between corrosion science and the nucleation and growth of the anodic aluminum oxide (AAO), while showing how the composition, microstructure, and quality of the base aluminum alloy are linked to the growth and the quality of the anodic oxide finish.
As an introduction to the book, Runge devotes the first two chapters to the history of aluminum and its alloys (Chapter 1) and the history of anodizing aluminum (Chapter 2). Together these chapters total 147 pages and comprise over 200 references. This teaching of history may appeal to science historians but seems excessive in light of the principal goal of teaching the metallurgy of anodizing aluminum. Perhaps one brief introductory chapter to the book would have sufficed to cover both of these introductory chapters (something to consider for the second edition?).
Chapter 3 – Anodizing as an Industrial Process is more apropos as an introduction to the anodizing process as we know it today. This chapter does a great job of summarizing all the features of industrial anodizing, AAO characteristics, and post-anodizing treatments in 30 pages with 46 references.
All aspects of the metallurgical principles behind anodizing aluminum are covered in the remaining five chapters of the book, beginning with Chapter 4 – Metallurgy Basics for Aluminum Surfaces. This sets the stage for Understanding Anodizing as a Corrosion Process (Chapter 5), AAO Growth and Structure (Chapter 6), Interfacial Phenomena and Anodizing (Chapter 7), and Base Metal Microstructural Considerations for Anodizing Aluminum Substrates (Chapter 8). Various examples and case studies of how basic physical metallurgy—variations in composition and microstructure of the anode—impacts the nucleation and growth of AAOs on different aluminum alloys are presented in detailed experimental images from the nano-scale to the micro-scale based on the latest microscopic techniques (AFM, TEM, SEM, and light microscopy). Many of these microscopic images come from Dr. Runge’s vast and impressive research activities in surface science applied to aluminum finishing as well as from different collaborative laboratories. Of particular help to readers are the very instructive graphics and illustrations that accompany the text and microscopic images, clarifying the metallurgy and mechanisms behind the nucleation and growth of AAOs.
Altogether, Runge’s The Metallurgy of Anodizing Aluminum belongs on the bookshelves of aluminum anodizing technologists, right next to Brace’s “bible.” At the same time, her book seems more the textbook choice for university courses in aluminum metallurgy and specialty courses on anodizing aluminum.
For info on how to obtain the book, visit: www.springer.com/us/book/9783319721750.