Star Of The Month Material - HyMu 80 Permalloy Soft Magnet Alloy

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Today, we'll delve into the market and review past customer orders to explore all the information about HyMu 80 (permalloy), a high-performance soft magnetic alloy.

 

In the fields of precision electronics, aerospace, and high-end instrument manufacturing, the magnetic properties of materials often determine the sensitivity and stability of core components. HyMu 80 alloy, a classic nickel-iron-molybdenum soft magnetic alloy, maintains an irreplaceable position due to its extremely high initial permeability and extremely low coercivity.

 

Next, I will share some limited experience with HyMu 80 alloy, hoping to help more users who want to learn about and purchase HyMu 80 alloy.

 

Multi-naming and industry standards

 

As we understand it, HyMu 80 has several well-known "identities" within the industry, with varying material naming conventions across different countries. For example, it belongs to the Permalloy family and, due to its approximately 80% nickel content, is often referred to as Permalloy 80. In terms of specific designation, it corresponds to the material indicated by MAG7904 and the US military standard MIL N-14411C Comp.1. Furthermore, the Chinese domestic material designation 1J85 is highly similar in composition and performance and is often used as a reference for domestic alternatives.

 

Regarding standards, HyMu 80 alloy primarily follows ASTM A753-78 (American Society for Testing and Materials) and ASTM F15, among other standards. These standards specify clear requirements for the material's magnetic properties, chemical composition, and heat treatment processes.

 

Customer orders

 

 

Material replacement product solutions

 

With technological advancements and cost considerations, some material alternatives have emerged in the market, such as 1J85 and permalloy 1J79.

 

Process Defects and Procurement Considerations

 

Despite its excellent performance, the material properties of HyMu 80 also present certain processing challenges. Feedback from Lork Group's internal and market procurement and technical personnel indicates the following points require special attention:

 

Heat Treatment Sensitivity: The magnetic properties of HyMu 80 are highly dependent on the final heat treatment process. It must be annealed for an extended period at 1000°C-1200°C in a pure hydrogen or high vacuum atmosphere to relieve stress and optimize grain orientation. Improper heat treatment will significantly reduce its magnetic permeability, even to the point of being inferior to ordinary silicon steel. Therefore, the production loss of this type of material is high, the yield rate is low, and the material price is 4-9 times higher than that of general magnetic materials.

 

Impurity Sensitivity: The material is extremely sensitive to impurities such as carbon, sulfur, and phosphorus. Even trace amounts of impurities can significantly increase coercivity and impair magnetic properties. Therefore, vacuum melting is a fundamental prerequisite for ensuring material purity. To our knowledge, there are only 5-10 factories in China with the necessary equipment and procedures for vacuum melting.

 

Work hardening: During cold working (such as cold drawing into tubes), the material hardens rapidly, which not only increases the difficulty of processing but also damages its magnetic properties. Therefore, users must specify whether to purchase HyMu 80 alloy in the "annealed state" or "hard state".