Sendust is a magnetic metal powder that was invented by

Hakaru Masumoto Hakaru Masumoto (1895–1987) was a pioneer in metal and alloy research. He discovered numerous superior and unique alloys, and contributed to improving the performance of precision machinery. A student of Kotaro Honda, Masumoto developed a mag ...

Tohoku Imperial University , or is a Japanese national university located in Sendai, Miyagi in the Tōhoku Region, Japan. It is informally referred to as . Established in 1907, it was the third Imperial University in Japan and among the first three Designated National ...

Sendai is the capital Cities of Japan, city of Miyagi Prefecture, the largest city in the Tōhoku region. , the city had a population of 1,091,407 in 525,828 households, and is one of Japan's 20 Cities designated by government ordinance of Japan, desig ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

circa 1936 as an alternative to

permalloy Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content. Invented in 1914 by physicist Gustav Elmen at Bell Telephone Laboratories, it is notable for its very high magnetic permeability, which makes it useful as a ...

inductor An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a c ...

applications for telephone networks. Sendust composition is typically 85%

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

, 9%

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...

and 6%

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

. The powder is

sintered Clinker nodules produced by sintering Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing ...

into cores to manufacture inductors. Sendust cores have high

magnetic permeability In electromagnetism, permeability is the measure of magnetization that a material obtains in response to an applied magnetic field. Permeability is typically represented by the (italicized) Greek letter ''μ''. The term was coined by William ...

(up to 140 000), low loss, low coercivity (5 A/m) good temperature stability and saturation flux density up to 1 T. Due to its chemical composition and crystallographic structure Sendust exhibits simultaneously zero

magnetostriction Magnetostriction (cf. electrostriction) is a property of magnetic materials that causes them to change their shape or dimensions during the process of magnetization. The variation of materials' magnetization due to the applied magnetic field change ...

and zero

magnetocrystalline anisotropy In physics, a ferromagnetic material is said to have magnetocrystalline anisotropy if it takes more energy to magnetize it in certain directions than in others. These directions are usually related to the principal axes of its crystal lattice. I ...

constant K₁. Sendust is harder than permalloy, and is thus useful in abrasive wear applications such as magnetic

recording head A recording head is the physical interface between a recording apparatus and a moving recording medium. Recording heads are generally classified according to the physical principle that allows them to impress their data upon their medium. A record ...

External links

Comparison of molybdenum permalloy with sendust
as energy storage inductors (

PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

file)
Sendust properties
{{alloy-stub Magnetic alloys Ferrous alloys Ferromagnetic materials

See also

External links