Click image to view full size image
AlNiCo ring magnet is a type of permanent magnet which primarily composed of a combination of Aluminum, Nickel, Cobalt, and Iron. Copper, Titanium, and Niobium is also added to the alloy to improve intrinsic coercivity. AlNiCo magnets are renowned for its excellent temperature stability and resistance to corrosion. The most representative applications of AlNiCo ring magnet include speedometer magnets, loudspeaker, and infrared guided missile magnets.
http://www.broad-magnet.com/