Refractory Metals & Powder Metallurgy

Refractory Metals & Powder Metallurgy

Due to their high melting points and hardness, the refractory metals are most often processed in powder form and never fabricated by casting.

Metal powders are manufactured to specific sizes and forms, then blended to create the right mixture of properties, before being compacted and sintered.

Sintering involves heating the metal powder (within a mold) for a long period of time. Under heat, the powder particles begin to bond, forming a solid piece.

Sintering can bond metals at temperatures lower than their melting point, a significant advantage when working with the refractory metals.

 

Carbide Powders

One of the earliest uses for many refractory metals arose in the early 20th century with the development of cemented carbides.

Widia, the first commercially available tungsten carbide, was developed by Osram Company (Germany) and marketed in 1926. This led to further testing with similarly hard and wear resistant metals, ultimately leading to the development of modern sintered carbides.

The products of carbide materials often benefit from mixtures of different powders. This process of blending allows for the introduction of beneficial properties from different metals, thereby, producing materials superior to what could be created by an individual metal. For example, the original Widia powder was comprised of 5-15% cobalt.