CVD法制备工艺参数对6.5%Si硅钢脆性的影响

发布时间：2018-05-02 16:30

本文选题：6.5%Si硅钢 + CVD　；参考：《华东理工大学》2015年硕士论文

【摘要】：硅钢的性能与所含硅含量存在密切关系,随着硅含量的升高电阻率和导磁率逐渐升高,而铁损逐渐降低。当硅含量达到6.5%时,硅钢将表现出超高磁导率、超低铁损以及几乎为零的磁致伸缩等优良特性。但随着硅含量的提高,硅钢将变的既脆又硬,其韧性和延展性急剧降低,导致传统的轧制技术很难用于制备6.5%Si硅钢,CVD法能够避免轧制成材率低的状况,但试样力学性能与CVD制备工艺条件如温度、气氛含氧量、SiCl4浓度和基材状况等有着密切的关系。本文通过CVD制备6.5%Si硅钢,研究不同工艺参数对硅钢脆性的影响并对改善其脆性具有极其重要的意义。本文简述了CVD法制备6.5%Si硅钢的实验设备、制备过程,以及真空反应炉反应温度和气氛含氧量的测试和控制方法,并通过实验验证了SiCl4浓度和水浴温度的关系,确定了CVD反应的升温方式。各工艺条件确定之后,根据单一控制CVD制备工艺制备出不同力学性能的6.5%Si硅钢试样。为了定量的分析6.5%Si硅钢的脆性,自主设计制造了三点压弯机,通过比较下压量和载荷位移曲线评价试样韧性。根据脆性测试结果进一步对试样进行电镜观察、EDS能谱分析和SEM断口扫描等微观组织分析。通过对不同工艺参数制备试样的脆性分析研究了粗大晶粒、晶界氧化和Kirkendall空洞对6.5%Si硅钢脆性的影响规律,结果表明应合理控制反应温度,尽可能降低气氛含氧量,并且减小SiCl4浓度来降低6.5%Si硅钢脆性：通过改变基材状况研究了退火处理和微量元素Sn对6.5%Si硅钢脆性的影响,结果表明基材退火导致晶粒不均匀长大使试样脆性增大,Sn促使Si均匀扩散使试样脆性降低。
[Abstract]:The properties of silicon steel are closely related to the silicon content. With the increase of silicon content, the resistivity and magnetic conductivity increase gradually, but the iron loss decreases gradually. When the silicon content reaches 6.5, the silicon steel will exhibit high permeability, ultra-low iron loss and almost zero magnetostriction. However, with the increase of silicon content, silicon steel will become brittle and hard, and its toughness and ductility will decrease sharply, which makes it difficult for traditional rolling technology to be used to prepare 6.5%Si silicon steel. However, the mechanical properties of the samples are closely related to the preparation conditions of CVD, such as temperature, oxygen content in atmosphere and the condition of the substrate. In this paper, 6.5%Si silicon steel was prepared by CVD. The influence of different process parameters on the brittleness of silicon steel was studied, and it was of great significance to improve the brittleness of silicon steel. In this paper, the experimental equipment and process of preparing 6.5%Si silicon steel by CVD method are briefly described, as well as the test and control methods of reaction temperature and oxygen content in atmosphere in vacuum reactor. The relationship between the concentration of SiCl4 and the temperature of water bath is verified by experiments. The heating mode of CVD reaction was determined. Different mechanical properties of 6.5%Si silicon steel samples were prepared according to the single controlled CVD process after each process was determined. In order to quantitatively analyze the brittleness of 6.5%Si silicon steel, a three-point bending machine was designed and manufactured. According to the results of brittleness test, the microstructures of the samples were further analyzed by electron microscope, EDS energy spectrum analysis and SEM fracture scanning. The effects of coarse grain size, grain boundary oxidation and Kirkendall voids on the brittleness of 6.5%Si silicon steel were studied by analyzing the brittleness of samples prepared with different process parameters. The results showed that the reaction temperature should be controlled reasonably and the oxygen content in atmosphere should be reduced as much as possible. By reducing the concentration of SiCl4 to reduce the brittleness of 6.5%Si silicon steel, the effects of annealing treatment and trace element Sn on the brittleness of 6.5%Si silicon steel were studied by changing the substrate condition. The results show that annealed substrate leads to uneven grain growth resulting in the increase of specimen brittleness and the decrease of specimen brittleness due to Si homogenization diffusion caused by Sn.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG142

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