氧化镁中硼含量对取向硅钢底层和磁性能的影响OA

Magnesium oxide(MgO)coating applied on the surface of grain-oriented silicon steel serves as a critical precursor for the formation of the magnesium silicate bottom layer.During manufactur-ing,various additives are introduced into the MgO coating system,among which boron-containing addi-tives exhibit a significant influence on the formation of the magnesium silicate glass film.The magnesium oxide with different boron contents was coated on the specimen surface,and the high-temperature annea-ling process of grain-oriented silicon steel was simulated in the laboratory.The morphology of the mag-nesium silicate glass film and the boron nitride in the specimens during the formation of the bottom layer was observed by focused ion beam microscopy(FIB),and its composition was analyzed by energy disper-sive spectroscopy(EDS).The results show that:(1)Boron oxide,as a low-melting-point substance,can accelerate the formation of the magnesium silicate interlayer.(2)The diffusion rate of boron is the main factor affecting the reaction between boron oxide and aluminum nitride.(3)Boron diffusion mainly occurs along grain boundaries.As the temperature increases,the provided energy gradually overcomes the lattice potential barrier,leading to an increase in bulk diffusion through lattice interstices and vacancies.(4)An appropriate amount of boron can effectively react with unstable surface inhibitors such as silicon ni-tride(Si3 N4)or aluminum nitride(AlN)to form fine boron nitride(BN)inhibitors,improving their sta-bility and increasing the secondary recrystallization temperature.However,excessive boron can destroy a-luminum nitride inhibitors,resulting in a loss of inhibition capability.