Heavy metal alloys are pseudo-alloys of tungsten with a nickel-iron or nickel-copper matrix. They are produced by powder metal and sintering processes.
The most outstanding property of heavy metal alloys is the high density of 17-19 g/cm³. Comparable densities are only reached by gold or platinum metals, which are considerably more expensive. Other exotic materials like rhenium, uranium or tantalum achieve these densities, but are either too difficult or expensive to obtain, or they have unsatisfactory mechanical characteristics.
Other advantages of Densalloy® heavy metal alloys are their extremely high Young's modulus of elasticity and high absorption coefficient for ionizing radiation, such as gamma radiation or high-energy X-radiation. Their machinability is better than that of pure tungsten.
Heavy metals properties
Sophisticated techniques of powder metallurgy make it possible to combine the low level of consumption of tungsten and the high electrical conductivity of copper into one material. Tungsten copper alloy is manufactured by compressing tungsten powder into a porous basic body. During sintering under vacuum, the cavities are soaked with liquid copper. Through variations of the manufacturing parameters (soaking metals, compressing and sintering conditions), the properties can be adapted to the application.
Contact and electrode materials have to fulfill stringent requirements concerning their electric conductivity while offering low levels of consumption by the electric arc.
Kennametal tungsten copper alloys have: