当前位置: X-MOL 学术Russ. J. Non-ferrous Metals › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Formation Kinetics of the Dielectric Coatings on Iron Powders for the Fabrication of Soft Magnetic Composite Materials
Russian Journal of Non-Ferrous Metals ( IF 0.8 ) Pub Date : 2020-09-03 , DOI: 10.3103/s1067821220040057
B. G. Gasanov , V. G. Tamadaev , V. O. Bogachev , E. R. Makhmudova

The topicality and efficiency of applying a silicate-containing inorganic coating as an electric insulator when producing soft magnetic composite materials (SMCMs) from iron powders are substantiated. The influence of the sodium silicate (Na2O–SiO2) concentration in an aqueous solution on the formation kinetics of the dielectric coating on iron powders of various brands is shown as well as on their weight increment, average coating thickness, and physical and manufacturing characteristics. It is established experimentally that the influence of particle morphology of iron powders and surface-tension coefficient at the liquid–solid interface on the coating thickness can be indirectly evaluated by wettability characteristics, in particular, by the contact angle. The peculiarities of formation of interlayer SMCM boundaries are considered. Elemental mapping using an energy-dispersive microanalyzer shows that the coating thickness changes after sample compaction under a pressure of 600 MPa and subsequent heating in a range of 400–600°C, and silicon partially redistributes in the dielectric layer. This is caused by the fact that silicon, having a higher oxygen affinity when compared with iron, actively reacts with oxygen arranged on the surface of iron particles and/or reduces iron oxides, forming SiO2 dioxide in the form of a dense film, which, on the one hand, protects iron particles against oxidation, and on the other hand, the dielectric layer affecting specific magnetic losses is formed in the contact zone of iron particles. It is established that the distinctive feature of densification of iron powders with the coating is the prevalence of the structural deformation under compacting, because the coating reduces the internal friction coefficient. It is shown that the developed SMCM corresponds to modern requirements demanded of soft magnetic composite materials in regards to its magnetic characteristics.

中文翻译:

铁粉上软磁复合材料的介电涂层形成动力学。

从铁粉生产软磁复合材料(SMCM)时,证实了将含硅酸盐的无机涂层用作电绝缘体的时事性和效率。硅酸钠(Na 2 O–SiO 2示出了水溶液中的浓度对各种品牌铁粉上介电涂层形成动力学的影响,以及它们的重量增量,平均涂层厚度以及物理和制造特性。通过实验确定,可以通过润湿性,尤其是通过接触角间接评估铁粉的颗粒形态和液-固界面处的表面张力系数对涂层厚度的影响。考虑了层间SMCM边界形成的特殊性。使用能量分散微分析仪的元素图谱显示,在600 MPa的压力下压实样品并随后在400-600°C的范围内加热之后,涂层厚度会发生变化,并且硅会部分重新分布在介电层中。致密膜形式的氧化钛,一方面可保护铁颗粒免受氧化,另一方面可在铁颗粒的接触区形成影响特定磁损耗的介电层。已经确定,通过涂层致密化铁粉的独特特征是在压实下结构变形的普遍性,因为涂层降低了内部摩擦系数。结果表明,所开发的SMCM就其磁性而言,符合软磁复合材料的现代要求。
更新日期:2020-09-03
down
wechat
bug