ASTM 596 / HYMU 80 / Mumetal 80 Alloy

Mumetal 80 is a versatile and high-performance alloy that offers exceptional magnetic shielding properties across a wide range of applications. Mumetal is 80% nickel with additions of iron and molybdenum as main elements in turn this alloy offers an extremely high initial permeability.

 

It is only moderately resistant to moisture and atmospheric corrosion, it used mainly in in transformer cores but is well known for its magnetic properties which are used for shielding electrical components from magnetic fields. “HYMU 80″ has a minimum DC permeability of 80,000 at a flux density of 40 gauss when heat treated by the recommended procedure and test in accordance with ASTM 596.

Mumetal 80 is non-hardenable by heat treatment, which means that its mechanical properties are primarily achieved through annealing. The annealing process typically involves heating the alloy to approximately 800°F (427°C) for several hours to achieve optimal properties. This process enhances the strength and toughness of the alloy.

Its unique chemical composition, combined with its ability to withstand extreme temperatures and harsh environments, makes it a preferred choice in industries such as aerospace, medical, and telecommunications. Understanding the fabrication techniques and standards associated with Mumetal 80 is essential for maximizing its performance and ensuring reliability in critical applications.

The thermal properties of Mumetal 80 are also noteworthy. The alloy exhibits good thermal conductivity, which is beneficial in applications where heat dissipation is critical. The thermal conductivity of Mumetal 80 at 20°C is approximately:

This property, combined with its low thermal expansion coefficient, makes Mumetal 80 an excellent choice for precision applications.

Cold working can be performed using standard tooling, but it is advisable to avoid using plain carbon tool steels, as they can cause galling. Soft die materials containing bronze and zinc alloys are recommended to minimize galling and provide a neat finish. Heavy-duty lubricants should be used to reduce galling during all forming operations.

 

As industries continue to evolve and demand materials that can withstand increasingly challenging conditions, Mumetal 80 will remain a vital component in the development of advanced technologies and solutions.