[en] Ion implantation as a method for the treatment of metals to improve, for instance, their resistance to wear and corrosion, is reviewed from the standpoint of general principles. A closely related technique, in which ion bombardment is used to enhance the properties of deposited coatings, is briefly set in perspective as a means of extending the scope for the application of industrial equipment. A few industrial examples are given to show how ion implantation can have important economic benefits, especially when carried out on a large scale. (author)