| As a new material product, the metallic fiber has been developed in the past 20 years. It not only has some its owner excellent properties, such as heat-resistance, corroding-resistance, electric conduction, heat-conduction, pliable and spinning. And when the metallic materials were processed for the fibers, the remarkable change had taken place in the inner microstructure, magnetic, resistivity and surface performance of the raw materials; demonstrate the characteristic different from general body material.In this paper, the magnetic, electric and mechanics performance change laws of the stainless steel fibers(SM: SS fiber), which were made through bundle drawing, were systematical studied. The results showed that the magnetism change of S S fibers was caused by many factors, however, the phases change, brought by internal-stress, was a reason of the high magnetism of fiber. The stainless steel composition had important influence on the magnetic properties of the fiber. The change of composing phases, the internal-stress and microstructure had insignificant effects on the magnetic properties for the S S fiber. As the fibers' diameter reduced to 2 urn; some magnetic properties of it were like as nanometer-soft-magnetism. With the reducing of S S fibers' diameter, the axial conductance rate of the fiber was reduced, the resistance increased. The reasons were about to the distortion of crystalline grain of metal, caused by cold-working, and size-effect of the fibers.In this paper, the effect of heat treatment on the magnetic properties of S S fibers was studied. Analyses showed that the effect of heat treatment is remarkable to 304 stainless steel fibers. And a new Martensitic phases formed, and Ms increased during annealing at 180C;annealing above 180C decreased the Ms. After annealed in the range of 380C~440 C ,the He increased and the product(Mr Hc)improved. It was also shown that annealing affected the mechanical properties of 316L SS fibers obviously.The Austenitic stainless steel fiber bindles and fiber/Cu composite were investigated. Ms of the S S fiber/Cu composite is much better than that of S S fiber bindles in some temperature range. The Metastable Austenitic phase of S S fiber at the interface of the fiber/Cu composite would turn back to equilibrium with the interfacial energy and inter stain inducing, when the Cu films were separated from S S fiber. So the magnetism value of the S S fiber declined. The information of grain-orientation at the interface of the fiber /Cu composite can serve as a mechanism responsible for its declining coercivity, and a part of Cu elements diffused into S S fibers.Several factors, which influenced electromagnetic parameters of stainless steel fiber, were discussed. From the experimental results, we studied the relationship between the diameter of fiber, the composition of S S and the impacts upon the electromagnetic parameter of fibers. Get following conclusions: both the complex permeability and the complex permittivity of SS fibers decreased with the increase of diameter in some region, the complex permittivity of 304 SS fibers, 2 m in diameter, could be up to 2.5 at the 2 GHz, the 302 SS fibers had better frequency dispersion properties than others, agreed with the requirements of the wide-band radar absorbing material in the range of 2GHz~12GHZ.The performance of the stainless steel fiber depended on its microstructure, and micro institutional framework was affected by the processing for fiber, such as drawing, heat treatment technology. Fiber performance influenced the performance of the fibers' production directly. The research of this thesis, to improve technology of fiber preparing, raise stainless steel fiber performance and open up its application, would offer experimental data and theoretical foundation, and make SS fiber meet the demands of other fields. |
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