Alnicos ;are a group of heat-treated Fe–Co–Ni–Al–Cu alloys that can be divided into two main subgroups: isotropic alloys containing 0–20 wt.% Co (alnicos 1–4) and anisotropic alloys with 22–24 wt.% Co and titanium content of 5–8 wt.% (alnicos 5–9). The anisotropy in the case of alnicos 5–9 is produced by controlled cooling or isothermal heat treatment in a saturating magnetic field. The main source of anisotropy is the shape anisotropy associated with elongated Fe–Co particles in a Ni-Al matrix aligned parallel to the magnetic field during spinodal decomposition of the alloy. Alnicos are widely used as permanent magnets. The most important applications are loudspeakers, watt-hour meters, electric motors, generators, and alternators.

Samarium–cobalt magnet

A samarium–cobalt (SmCo) magnet, a type of rare-earth magnet, is a strong permanent magnet made of two basic elements: samarium and cobalt.FeCrCo/Crovac ;as a new type of magnet has come into the world in the 1970s. It is widely used in space, aviation, shipping instrument, automobile instrument, magnetic motor, compasses, computer embroider machines and signal systems, etc.

FeCrCo/Crovac has good plasticity, ductility, and machining ability. And can be drilled, planned, stamped, and other machining operations. The minimum diameter can be 0.05 mm and the thickness of the strip can be 0.1 mm, especially suited for tinny elements with accurate dimensions and complicated shapes, such as strip, wire, bar, tube, etc.

FeCrCo/Crovac has excellent temperature stability, good corrosion resistance, and a high Curie temperature(around 680). The maximum working temperature is 400.

Neodymium magnet

A neodymium magnet (also known as NdFeB, NIB, or Neo magnet) is the most widely used] type of rare-earth magnet. It is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd2Fe14B tetragonal crystalline structure. Developed independently in 1984 by General Motors and Sumitomo Special Metals, neodymium magnets are the strongest type of permanent magnet available commercially.

NdFeB ;magnets can be classified as sintered or bonded, depending on the manufacturing process used. They have replaced other types of magnets in many applications in modern products that require strong permanent magnets, such as electric motors in cordless tools, hard disk drives, and magnetic fasteners.Cast Alnico ;was first developed in the 1930s and uses Aluminum, Nickel, and Cobalt from the lowest levels of Alnico Bonded up to Alnico 10 which is a hot mold exothermic material. This requires great foundry and heat-treating expertise. It is still widely used in watt-hour meters, instruments, and some holding devices such as pot magnets and medical devices. ;

Cast Alnico 5 is the most commonly used of all the cast Alnicos. This material is used extensively in rotating machinery, meters, instruments, sensing devices, and holding applications, to name a few.1. The use temperature of the Sintered AlNiCo ;magnets can be as high as 450-500 degrees Celsius. Besides, they come with a small magnetic output change and temperature change among the permanent magnets.

2. Although the magnetic properties of sintered AlNiCo magnets are slightly lower than those of the cast AlNiCo magnets, their mechanical properties are much better.

3. The size and dimensional tolerances of Sintered AlNiCo Magnets are relatively smaller than those of cast magnets and do not require much further processing.Sintered NdFeB ;magnets, i.e. sintered neodymium iron boron magnets, are those permanent magnetic materials based on an Nd-Fe-B tetragonal crystal structure. Sintered NdFeB magnets were invented by M. Sagawa’s team in the early 1980s, they are manufactured through a powder metallurgy process.