高磁性元素含量Fe基块体非晶合金制备与性能研究

发布时间：2018-05-01 17:03

本文选题：Fe基合金 + 合金化　；参考：《清华大学》2015年博士论文

【摘要】：Fe基块体非晶合金具有高强度、耐腐蚀以及优异的软磁性能,是一种应用前景广阔的功能与结构材料,然而大多数Fe基块体非晶合金存在饱和磁极化强度偏低,非晶形成能力不足和室温塑性变形能力差等问题,严重制约了它们的应用。因此,研究影响Fe基非晶合金的非晶形成能力和饱和磁极化强度的重要因素,开发同时具有高的非晶形成能力和饱和磁感应极化强度的Fe基非晶具有重要意义。本文通过合金化和包覆剂提纯的方法开发出Fe82Mo1P6.5C5.582Si3和Fe81P8.5C5.582Si3块体非晶合金,其中Fe82Mo1P6.5C5.582Si3非晶合金是迄今报道Fe含量最高的块体非晶合金。在Fe81Mo1P7.5C5.582Si3合金中,发现采用Co替换Fe元素可显著提高该合金系的非晶形成能力和饱和磁极化强度。通过包覆剂提纯和铜模铸造联用的方法制备的Fe66Co15Mo1P7.5C5.5B2Si3合金的非晶形成临界尺寸由加Co前的1.0 mm提高到2.0 mm。并在此基础上,通过进一步调整成分和提高磁性元素Fe和Co的总含量,制备出Φ1.4 mm的Fe67Co15Mo1P6.5C5.5B2Si3和Φ1.0 mm的Fe67Co16Mo1P5.5C5.5B2Si3块体非晶合金。其中Fe67Co16Mo1P5.5C5.5B2Si3块体非晶合金饱和磁极化强度达1.70 T,是目前饱和磁极化强度最高的块体非晶合金。通过调控退火工艺可在Fe67Co16Mo1P5.5C5.5B2Si3非晶合金中析出均匀分布α-Fe(Co)纳米晶化相,获得了饱和磁极化强度达2.11 T的纳米晶Fe基合金。研究发现Ni替代Fe的方法可显著提高Fe81Mo1P7.5C5.5B2Si3合金的非晶形成能力和压缩塑性。通过包覆剂提纯和铜模铸造联用的方法制备的Fe71NiloMo1P7.5C5.5B2Si3合金的非晶形成临界尺寸由加Ni前的1.0mm提高到2.5mm。而Fe61Ni2oMo1P7.5C5.5B2Si3的压缩塑性由加Ni前的0.3%提高到了3.2%。采用化学镀的方法在Fe81Mo1P7.5C5.5B2Si3块体非晶表面镀覆了厚度约为5μm与基体结合力好且均匀的镍镀层,合金的压缩塑性从0.3%提高到8%。结果表明薄镀层也能够有效促进剪切带的形核和阻碍剪切带的快速扩展,从而提高Fe基非晶的塑性变形量。
[Abstract]:Fe-based bulk amorphous alloys have high strength, corrosion resistance and excellent soft magnetic properties, so they are widely used as functional and structural materials. However, most Fe-based bulk amorphous alloys have low saturation magnetic polarization. Their application is seriously restricted by the shortage of amorphous forming ability and the poor plastic deformation capacity at room temperature. Therefore, it is of great significance to study the important factors affecting the amorphous formation ability and saturation magnetic polarization of Fe-based amorphous alloys, and to develop Fe-based amorphous alloys with high amorphous formation ability and saturation magnetic induction polarization. Fe82Mo1P6.5C5.582Si3 and Fe81P8.5C5.582Si3 bulk amorphous alloys have been developed by alloying and coating agent purification. Fe82Mo1P6.5C5.582Si3 amorphous alloys are the bulk amorphous alloys with the highest Fe content reported so far. In Fe81Mo1P7.5C5.582Si3 alloy, it is found that the substitution of Fe with Co can significantly improve the amorphous formation ability and saturation magnetic polarization of the alloy system. The critical size of amorphous formation of Fe66Co15Mo1P7.5C5.5B2Si3 alloy prepared by the combination of coating agent purification and copper mold casting was increased from 1.0 mm to 2.0 mm before Co addition. On this basis, by further adjusting the composition and increasing the total content of magnetic elements Fe and Co, 桅 1.4 mm Fe67Co15Mo1P6.5C5.5B2Si3 and 桅 1.0 mm Fe67Co16Mo1P5.5C5.5B2Si3 bulk amorphous alloys were prepared. The saturation magnetic polarization strength of Fe67Co16Mo1P5.5C5.5B2Si3 bulk amorphous alloy is 1.70 T, which is the highest in bulk amorphous alloy at present. Nanocrystalline Fe-base alloys with saturation magnetic polarity of 2.11T were obtained by controlling annealing process to precipitate 伪 -FeCo) nanocrystalline phases in Fe67Co16Mo1P5.5C5.5B2Si3 amorphous alloys. It is found that the amorphous forming ability and compression plasticity of Fe81Mo1P7.5C5.5B2Si3 alloy can be improved by the substitution of Ni with Fe. The critical size of amorphous formation of Fe71NiloMo1P7.5C5.5B2Si3 alloy prepared by the combination of coating agent purification and copper mold casting was increased from 1.0mm before Ni addition to 2.5 mm. The compressive plasticity of Fe61Ni2oMo1P7.5C5.5B2Si3 increased from 0.3% to 3.2% before Ni addition. Electroless plating method was used to coat the amorphous surface of Fe81Mo1P7.5C5.5B2Si3 with nickel coating with good adhesion to the substrate with a thickness of about 5 渭 m. The compressive plasticity of the alloy was increased from 0.3% to 8%. The results show that thin coating can also effectively promote the nucleation of shear band and hinder the rapid expansion of shear band, thus increasing the plastic deformation of Fe-based amorphous.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG139.8

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