Grain boundary diffusion process(GBDP)is a widely used method of increasing the coercivity of sintered NdFeB magnets.In this study,the effects of the GBDP on the bending strength and microhardness of sintered NdFeB ma...Grain boundary diffusion process(GBDP)is a widely used method of increasing the coercivity of sintered NdFeB magnets.In this study,the effects of the GBDP on the bending strength and microhardness of sintered NdFeB magnets and the fracture mode were investigated.Results show that the bending strength of magnets is reduced by pickling and heat treatment and greatly recove rs after heavy rare earth element(Tb)grain boundary diffusion.The pickling and the heat treatment cause a slight decrease in microhardness.Compared with the recovery of the bending strength,the hardness decreases after the GBDP.The fracture mode of bended magnets changes from intergranular to transgranular.This study helps in further improving the mechanical and magnetic properties of sintered NdFeB magnets.展开更多
By virtue of the singular point theory for one-dimension diffusionprocess and the stochastic averaging approach of energy envelop, thebifurcation behavior of a homoclinic bifurcation system, which is inthe presence of...By virtue of the singular point theory for one-dimension diffusionprocess and the stochastic averaging approach of energy envelop, thebifurcation behavior of a homoclinic bifurcation system, which is inthe presence of parametric white noise and is concealed behind acodimension two bifurcation point, is investigated in this paper.展开更多
基金Project supported by the National Key Research and Development Program of China(2021YFB3502902)the Key Research and Development Program of Ningbo(2021Z024)。
文摘Grain boundary diffusion process(GBDP)is a widely used method of increasing the coercivity of sintered NdFeB magnets.In this study,the effects of the GBDP on the bending strength and microhardness of sintered NdFeB magnets and the fracture mode were investigated.Results show that the bending strength of magnets is reduced by pickling and heat treatment and greatly recove rs after heavy rare earth element(Tb)grain boundary diffusion.The pickling and the heat treatment cause a slight decrease in microhardness.Compared with the recovery of the bending strength,the hardness decreases after the GBDP.The fracture mode of bended magnets changes from intergranular to transgranular.This study helps in further improving the mechanical and magnetic properties of sintered NdFeB magnets.
基金Supported by the National Science Foundation of China under Grant No.19602016
文摘By virtue of the singular point theory for one-dimension diffusionprocess and the stochastic averaging approach of energy envelop, thebifurcation behavior of a homoclinic bifurcation system, which is inthe presence of parametric white noise and is concealed behind acodimension two bifurcation point, is investigated in this paper.
