# Platinum as a Metallic Material

## Oxide Dispersion Hardening

Fig.1
TEM micrograph

The figure shows a TEM micrograph of containing a large number of oxide particles in the size range 200-300$nm$.

Oxide dispersion hardened platinum materials have been known for many years and are produced by a variety of techniques that are largely proprietary (e.g. thermal spraying and dynamic oxidation of a platinum-zirconium alloy or powder metallurgical processing of a platinum-zirconium alloy). Heraeus manufactures oxide dispersion hardened platinum materials (DPH1)) by a melting and casting process in which platinum and its alloys are doped with reactive metals (e.g. zirconium, yttrium, cerium, scandium) before casting.

The cast ingot is forged, worked down to a thick walled intermediate product and exposed to an oxidizing atmosphere at an elevated temperature. During this process, the reactive metals oxidize almost completely inside the platinum matrix; the process is known as internal oxidation. The internally oxidized material is then formed and fabricated to the finished product.

The material contains a large number of oxide particles in the size range 200-300$nm$. Extremely fine particles down to 10$nm$ are also to be found that are stable even under the simultaneous influence of high temperature and creep loadings.

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