Experimental Researches On The Fe-Co-Ni Based Microwave Absorbing Composites

Simple equipments, easy controlling are the advantages of polyol process to synthesize ultra-fine alloy particles. So polyol process is concerned home and abroad. The Fe-Co-Ni fine alloy particles synthesized in polyol process have the shape of global or approximate global and with the composite structure of "shell- cores", the granularity distribute from nanometer to micron and it is very easy to control. And the particles have good dynamic microwave electromagnetic property. Because these advantages of polyol process, it will be a focal point of synthesizing absorbent material.In this paper, a series Fex[CoyNi1-y]1-x fine particles were synthesized in polyol process. The theory and the basic method of polyol process were researched by experimentation. The method of the sol-gel and fine alloy particle's synthesizing, the particle's interface treatment and anneal, the coaxial sample's preparation were mastered. A lot of experience of experiment, parameter and data were accumulated. Fe-Si fine powder was prepared use MA method, and it's electromagnetic capability was analysed. It shows that Fe-Si was well used in low frequency, but it is not good as the microwave absorbing capability.In the experiment, the SEM was used to observe the microscopic feature of the Fe-Co-Ni fine alloy particles. The factors affecting the granularity and the microcosmic form were analyzed. The mould to make the coaxial sample was designed. The microwave electromagnetic properties from 30MHz to 6GHz of alloy particles were measured by vector network analyzer. And the data was calculated use Matlab. The fine Co-Ni alloy particles and fine Co particles was synthesized in the same process to analyze the composition's effecting to the fine alloy particles' microwave electromagnetic properties. And the Fe0.13[Co20Ni80]0.87 fine particles with different treatment were made into coaxial sample to analyze the effecting to the electromagnetic properties of modification and anneal.The results show that the electromagnetic parameters of alloy particles are improved and the granularity was reduced with suitable modification and treatment of magnetic particles. And it was found that the electromagnetic characterizations of the particles were varied with the different contents of Co.