Oxide Dispersion Hardening

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$\text{nm}$. Extremely fine particles down to 10$\text{nm}$ are also to be found that are stable even under the simultaneous influence of high temperature and creep loadings.