MKM steel, an alloy

Alloy

An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

 containing nickel

Nickel

Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...

 and aluminum, was developed in 1931 by the Japanese

Japanese people

The are an ethnic group originating in the Japanese archipelago and are the predominant ethnic group of Japan. Worldwide, approximately 130 million people are of Japanese descent; of these, approximately 127 million are residents of Japan. People of Japanese ancestry who live in other countries...

 metallurgist Tokuhichi Mishima

Tokuhichi Mishima

was a Japanese metallurgist. He discovered that aluminum restored magnetism to non-magnetic nickel steel. He invented MKM steel, which was an extremely inexpensive magnetic substance that has been used in many applications. It is also closely related to the modern Alnico magnets. He later...

. While conducting research into the properties of nickel, Mishima discovered that a strongly magnetic steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 could be created by adding aluminum to non-magnetic nickel steel.

MKM steel is tough and durable, inexpensive to produce, maintains strong magnetism

Magnetism

Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

 when miniaturized and can produce a stable magnetic force in spite of temperature changes or vibration. These properties made MKM steel ideal for various applications in the rapidly growing electronics

Electronics

Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

 sector and allowed the miniaturization of components used in personal electronics and the communications, aviation and automobile industries.

MKM is an acronym for Mitsujima ka magnetic, 'Mitsujima ka' being the name of the inventor's childhood home.

MKM steel is similar to Alnico

Alnico

Alnico is an acronym referring to iron alloys which in addition to iron are composed primarily of aluminium , nickel and cobalt , hence al-ni-co, with the addition of copper, and sometimes titanium. Alnico alloys are ferromagnetic, with a high coercivity and are used to make permanent magnets...

.