等离子喷涂制备磁铅石相结构铁氧体复合涂层研究

Study on Preparation of Ferrite Composite Coating with Magnetoplumbite Phase Structure by Plasma Spraying

为解决热喷涂直接制备磁铅石结构铁氧体涂层问题,采用等离子喷涂工艺制备了铁氧体/聚乙烯复合涂层,研究了复合涂层的相结构和微观组织形貌。结果表明:等离子喷涂铁氧体/聚乙烯复合涂层厚度为1 mm,涂层中同时存在尖晶石相和磁铅石相,尖晶石相占55%,磁铅石相占45%,涂层中存在大量的未熔相,未发现典型的层状结构。通过牺牲聚乙烯保护磁铅石铁氧体,喷涂过程中低熔点聚乙烯首先熔融烧蚀,带走了等离子焰流的部分热量,使一部分磁铅石铁氧体吸热不足不能充分熔融,未发生熔化冷却结晶以及从尖晶石晶型向磁铅石晶型的转化过程,而是保留了原始的磁铅石相结构沉积到涂层中。通过该方法使等离子喷涂制备了具有磁铅石结构铁氧体的复合涂层。

In order to solve the problem of direct preparation of magnetoplumbite phase structure ferrite coating by thermal spraying,the ferrite/polyethylene composite coating was prepared by plasma spraying process,and the phase structure and microstructure morphology of the composite coating were studied.Results showed that the thickness of ferrite/polyethylene composite coating was 1 mm.Spinel phase and magnetoplumbite phase existed simultaneously in the coating,with spinel phase accounting for 55%and magnetoplumbite phase accounting for 45%.In addition,many un-melted phases existed in the coating but there was no typical lamellar structure in the coating.By sacrificing polyethylene to protect the magnetoplumbite ferrite,the low melting point polyethylene was melted and ablated first in the spraying process,which took away part of the heat of the plasma flame flow,so that some magnetoplumbite ferrite had insufficient heat absorption and could not be fully melted.There was no melting cooling crystallization and the transformation process from spinel crystal form to magnetoplumbite crystal form,but retained the original magnetoplumbite phase structure deposited into the coating.Through this method,the composite coating of ferrite with magnetoplumbite structure was prepared by plasma spraying.