Corrosion-inhibiting protection for watch magnets, in particular neodymium-iron-boron magnets

A method for protecting a watch magnet against corrosion, comprising:

• preparing a surface of the watch magnet with a sandblasting operation;
• subjecting the sandblasted surface of the watch magnet to an ion implantation treatment in a plasma selected from the group consisting of an oxygen plasma and a nitrogen plasma, to obtain an outermost surface of the watch magnet having all surface bonds saturated by oxygen ions or nitrogen ions;
• wherein
• the watch magnet is a neodymium-iron-boron magnet is containing 22 wt % to 24 wt % neodymium, 65 wt % to 67 wt % iron, and 0.1 wt % to 2 wt % boron, and
• the outermost surface of the watch magnet having all surface bonds saturated by oxygen ions or nitrogen ions is an impervious oxidized or nitrided surface layer.