【作者】 张建红；

【导师】 章桥新；

【作者基本信息】 武汉理工大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 本文利用渗硼介质吸收微波的特性,研究了渗硼介质与微波相互作用的温度效应和两种微波腔（单模和多模）中钢铁表面渗硼层的制备。通过组织、形貌观察、结构测定、力学性能测试、腐蚀实验等对微波渗硼层进行了细致的研究,并与常规渗硼进行了比较。针对微波场中渗硼介质的温度采用红外测温只能测量渗剂表面温度,不能精确反应实验渗硼温度的问题,设计了一套用热电偶测温和控制的方法。 实验结果表明:通过适当的微波输出功率与相应渗硼介质的质量耦合可以实现较长时间的稳定温度,其温度高低可以通过微波输出功率或渗剂质量来调控。利甩渗硼介质吸收微波的特性可以实现碳钢表面渗硼层的制备,其渗层厚度随微波作用时间增加而增加。无论是单模腔还是多模腔,微波场下渗硼层的形成速率远大于常规渗硼,渗层组织特征与常规渗硼类似为锯齿状,渗层中的FeB、Fe₂B相均表现<002>取向生长特征,且渗层的形成是以形核长大方式进行的。微波场下的渗硼层形成所需的硼原子来源于介质分解的活性硼原子和气态硼化物分解的硼原子。其中活性硼原子对渗层生长速率的贡献大于气态硼化物分解的硼原子。 与常规渗硼渗层相比,微波渗硼的渗层硬度高、耐磨性好。但在15%硫酸和30%氢氧化钠溶液中的抗腐蚀能力比常规渗硼层差,在20%氯化钠中的抗腐蚀能力好于常规渗硼。更多还原

【Abstract】 In this paper, the temperature effect between boriding medium and microwave field and preparation of steels boriding in two microwave cavity （single-mould cavity and multi-mould cavity） were studied. The boriding medium can absorb microwave as the diffusion resource. The microwave boriding was carefully investigated by metallographic observation, SEM, X-ray diffraction and mechanics testing. Their properties were compared with those of conventional boriding. We also designed a novel temperature measurement and control device because the infrared thermoscope is not precise in microwave field.It is showed that the long-term stable temperature could be obtained by coupling the microwave power and the mass of boriding medium. The boriding temperature could be adjusted by either the microwave power or the mass of boriding medium. The thickness of boriding layer increases with the treating time. The boriding velocity in microwave field is faster than that in conventional boriding whatever in single-mould cavity or in multi-mould cavity. The microstructure of microwave boriding and conventional boriding has the same jagged characteristic. The Fe₂B phase and FeB phase grow along <002> tropism and form by nucleation and growth in both boriding methods. The activated boron atoms come from the boron atoms which decomposed by boriding medium and gaseous boride. It is proved that the activated boron atoms decomposed by boriding medium are more than those decomposed by gaseous boride.The hardness of microwave boriding is higher than that of conventional boriding. And their wear resistance are also better than that of conventional boriding. But their corrosion resistance is contradicted. The corrosion resistance of microwave boriding is better in 20% NaCl aqueous solution but less in 15% H₂SO₄ and 30% NaOH aqueous solution than that of conventional boriding.更多还原