Diffusion Bonding of Platinum
James Binnion • Binnion Metal Arts, LLC.

Over the past several years much has been written about the processes of fusion welding, laser welding and brazing for bonding platinum to itself and other metals. In this paper I would like to talk about a different method for bonding platinum: diffusion welding.

Diffusion Welding
The Merriam-Webster Dictionary defines diffusion as: "the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances

move from a region of higher to one of lower concentration". In diffusion welding two or more surfaces are joined by the diffusion process. To describe how this works, it is probably best to think of
an often-used simple model for the crystal structure of a metal.

In Figure 1 the spheres represent metal atoms in the idealized crystal lattice, however real world metal structures are not so neat. Impurities, the way the metal solidified, working stresses and many other factors make the lattice a much more unruly structure.

Platinum Guild International USA 2004   All Rights Reserved

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Figure 1: The Crystal Lattice

Figure 2: Vacancies in the crystal lattice