Study on mechanical properties of recycled sintered Nd-Fe-B magnets

The efficient regeneration of rare earth secondary resources of sintered Nd-Fe-B is of great significance for the recycling economy of rare earth resources. Since the mechanical properties of recycled magnets have a crucial impact on promoting its commercial application, tensile strength, compressive strength, hardness and fracture toughness of the original sintered Nd-Fe-B magnet and the recycled magnet were systematically studied and the mechanism was illustrated based on the analysis of the chemical composition and microstructure. The main fracture mechanism of recycled sintered magnets is intergranular fracture. The fracture toughness of recycled sintered magnets is slightly higher than that of original magnets, but the bending, compressive and hardness of recycled sintered magnets are slightly lower than that of original magnets. The differences in mechanical properties are mainly attributed to the higher content of rare earth and grain boundary phases in recycled magnets. In summary, the regenerated magnet has the similar mechanical properties as those of the original magnet, which can fully meet the requirements of the product.

Automated summary

The efficient regeneration of sintered Nd-Fe-B rare earth magnets plays a crucial role in the recycling economy of rare earth resources. This study systematically investigated the mechanical properties of the original and recycled magnets and analyzed the chemical composition and microstructure to explain the mechanism. The main fracture mechanism of recycled magnets is intergranular fracture. The regenerated magnets have similar mechanical properties to the original magnets, fully meeting product requirements.