This invention relates to
cemented carbide articles that are characterized by substantially improved
biocompatibility with
human skin, tissue, organs, etc., compared with articles made from conventional cemented carbides. The essential feature of these improved biocompatible
cemented carbide articles is a binder-depleted zone at and near the exposed surfaces of the articles. By depleting the binder (which mainly consists of Co and / or Ni, as well as their alloys) at and near the surface, the toxic effects of Co and Ni (known carcinogens), as well as the allergic reactions that these metals can cause when in contact with
human skin, are eliminated. By depleting the binder only at and near the surface, the bulk properties of the
cemented carbide article are not compromised or altered in any manner. Applications of these binder-depleted cemented carbides could include articles that
human skin may experience
prolonged exposure to, for example, jewelry articles such as rings, bracelets, bangles, chains, necklaces, pendants, watches, watch cases, watch straps, etc. In addition, the cemented carbides of this invention may be used in applications where the article comes directly in contact with human
skin, tissue, organs, etc. such as surgical and other
medical instruments, razor blades, etc. Also, other applications could include knives, tools, dies, and other wear components that are used to process and
handle, and hence, come into direct contact with materials meant for human consumption and / or
ingestion. Examples of such materials include foodstuffs and pharmaceuticals.