How to distinguish NdFeB magnet and AlNiCo magnet?

NdFeB magnet and AlNiCo magnet are common magnetic materials, how to distinguish NdFeB magnet and AlNiCo magnet?

Exterior

Appearance is the easiest way to judge NdFeB magnet and AlNiCo magnet.
NdFeB magnet is easily oxidized due to the metal-containing neodymium, so it needs surface plating. NdFeB magnet usually has more nickel and zinc coatings.
AlNiCo magnet has good corrosion resistance and usually does not undergo surface treatment.

Material

The fracture of the two products is different. NdFeB magnet is a very fine small crystal, while the section of AlNiCo magnet is rougher and the crystal particles are larger.

Curve detector

Judging by the demagnetization curve of these two magnetic materials, NdFeB magnet has higher remanence.