Abstract: Method for the preparation of permanent magnets at room temperature from an alloy containing at least a mixture of iron (Fe), boron (B) and rare earths (RE) including Yttrium, and for which there is a temperature range wherein said alloy is in two phases; one solid and brittle and the other one liquid. The method comprises heating said alloy under controlled atmosphere at a temperature sufficient to reach said temperature range, treating said alloy, and finally, optionally, allowing the treated alloy to cool. The method being characterized on the one hand in that said Fe-B-Re alloy is in a massive form, and on the other hand, in that the treatment of said massive alloy is carried out by welding of the magnetic solid phase Fe-B-Re.