Refractory metals are a small group of strong metals that have melting points beyond 2000 °C and are chemically inert. These qualities make refractory metals like Niobium, a useful substrate in a variety of industries. However, unlike light and common metals such as aluminum, copper, and nickel, refractory metals present a more unique challenge during their plating processes.
The biggest difference between plating onto refractory metals versus plating onto common metals is that the aqueous solution (chemical bath) used in the typical electroplating process is ineffective when trying to adhere ions to the surface of a refractory substrate. Other processes, like fused-salt electrolysis, must be done to properly plate directly onto a pure refractory metal such as Niobium or Tungsten
Refractory metals are often alloyed with other metals such as iron, nickel, and copper. This simultaneously improves the chemical and physical properties of the original light metals, while making it easier to plate/coat the surface of a refractory metal.