Permalloy is a metal alloy with a very high magnetic permeability. This makes the alloy useful in a wide range of applications when high magnetic permeability is desired. Easily magnetized and demagnetized, permalloy can be found working at sites which range from recording studios to electrical generation facilities. There are a number of different permalloy blends available from companies which specialize in producing this metal alloy, including specialty alloys which can be produced by request for specific projects.
Permalloy products contain a blend of iron and nickel. One common blend includes 80% nickel and 20% iron, although other formulations are available. Often, the metal will be identified as X permalloy, with X standing for the percentage of nickel in the blend. Thus, 35 permalloy contains 35% nickel. This standardized terminology is important when people discuss the production and use of this alloy, ensuring that everyone understands the composition of the blend in discussion.
One use for permalloy is in magnetic recording heads used in the sound industry, or used to record other types of data. Permalloy is also used in the production of inductors and electrical transformers. It has one of the highest magnetic permeability ratings of any metal or alloy, making it an industry standard in applications where metals with high magnetic permeability are needed.
This metal magnetizes and demagnetizes quickly and evenly, in contrast with other metals which exhibit magnetic properties. Various factors can influence the magnetic permeability of the permalloy, including the humidity, temperature, strength of the field used for magnetization, distance of the magnetic field, and so forth. These variables can be tightly controlled as needed by people working with the metal so that they can achieve the desired results for the application in which the metal is being used.
Facilities which make alloys exercise tight controls to make sure that impurities are kept to a minimum, as they can impact an alloy's performance. These facilities can control the blend of the alloy and use materials testing to confirm that an alloy has been blended properly. This can be especially important for delicate operations in which the reliability of the alloy being used is key to the outcome of the operation. Using the wrong alloy can become a safety issue or can skew performance results. Permalloy can also be processed to make superalloy, an alloy which contains molybdenum in addition to other permalloy components.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.