Aluminum nickel and cobalt (AlNiCo) is the first developed a kind of permanent magnetic material, is made of aluminum, nickel, cobalt, iron and other trace metal elements of a kind of alloy, high magnetic flux density, good time stability, high temperature resistant, corrosion resistance is one of its advantages, generally don't need to its product surface special treatment. In some application, smooth surface is preferred, however , they can be easily plated using a variety of metals, such as nickel or chrome.