Aluminium Alloys - A Century of Age Hardening

TLDR: A century has elapsed since Alfred Wilm made the accidental discovery of age hardening in an aluminium alloy that became known as Duralumin, and the gradual realization that hardening arose because of the presence of fine precipitates which provided barriers to the motion of dislocations, is a good example of the transition of metallurgy from an art to a science.

Abstract: A century has elapsed since Alfred Wilm made the accidental discovery of age hardening in an aluminium alloy that became known as Duralumin. His work, and the gradual realization that hardening arose because of the presence of fine precipitates which provided barriers to the motion of dislocations, is a good example of the transition of metallurgy from an art to a science. A brief account is given of the development of age hardenable aluminium alloys and the way that modern experimental techniques allow precipitation processes to be understood on an atomic scale. Some contemporary issues in age hardening are then discussed.