烧结NdFeB磁体强度和韧性研究现状

烧结NdFeB永磁材料具有磁性能高、价格低、生产工艺简单等突出优点，因而自其开发以来，生产和应用取得了快速发展，并且其市场还将不断扩大。但是，这种材料强度和韧性差，机械加工困难，应用过程中容易开裂。因此，改善烧结NdFeB永磁材料的力学性能已成为一个迫切的需要。综述了该种材料的断裂机制及在改善材料强度和韧性等方面所做的研究工作，认为通过添加合金元素，韧化晶界，细化主相晶粒，是一种有效的方法。研究表明，材料的断裂方式主要为沿晶断裂，晶界上的薄片富Nd相是引起沿晶断裂的主要原因，通过微量添加合金元素能有效改善磁体力学特性。

Developing Situation of Strength and Toughness of Sintered NdFeB Magnets

Since its development, the production and application of sintered NdFeB permanent magnets have grown rapidly, and the market will continue to expand. It is not only for their excellent magnetic properties and low price, but also for their simple preparation method. But the magnets have poor toughness strength and which result in poor machinability, and are easy to fracture during application. So it is important to improve their mechanical properties. The fracture mechanism and status of research on strength and toughness were reviewed. It shows that the fracture behaviour of the NdFeB magnets show mainly intergranular fracture. The intergranular Nd-rich film on the grain boundary is the main cause of the intergranular fracture. Slightly adding alloy elements is an effective way to improve the mechanical properties.