【作者】 吴文军；

【导师】 罗伯诚；

【作者基本信息】 四川大学 ， 原子与分子物理， 2006， 硕士

【摘要】 用Ni-Fe二元系合金作钎料，分别采用不同的钎焊温度、保温时间，成功地实现了金刚石与钢基体的钎焊连接。实验结果具有很好的重现性。用显微镜观测了金刚石在钎料上的分布情况，用扫描电镜对钎焊接头表面及其断面进行了仔细观察；X射线能谱仪给出了钎焊后金刚石与钎料中存在的元素及各元素在微区的含量分布情况。X射线衍射仪则给出了钎焊后金刚石与钎料中存在的各物质相。实验表明，钎焊时Ni-Fe合金中的Fe元素向金刚石表面扩散，并在钎料与金刚石的界面与金刚石中的碳反应生成碳化物Fe₅C₂。这是一种具有复杂晶格结构的间隙化合物。通过该碳化物的桥梁作用，实现了金刚石与基体的钎焊连接。从液体对固体的浸润性、溶解与扩散的理论可进一步得出，钎焊时金刚石向钎料溶解、钎料向金刚石扩散，由此形成的碳化物Fe₅C₂改善了钎料对金刚石的浸润性，提高了钎料对金刚石的可钎焊性。 在Ni-Fe合金作钎料的基础上，采用真空钎焊的方法，将钎焊金刚石样品制成钎焊金刚石磨轮；在生产现场进行了钎焊金刚石磨轮与传统磨轮的对照试验。试验结果表面，前者在磨耗比、锋利度、手持工作效果等磨削性能方面表现出比后者明显的优势，具有一定的工业应用前景。 分析了在Ni-Fe合金中加入少量活性元素Cr后，在钎焊中产生的物质相，结果表明钎料中的Cr元素优先向金刚石表面扩散并在金更多还原

【Abstract】 Using Ni-Fe alloy as the filler metal, the brazing joining is realized successfully between diamond and the steel substrate under the conditions of different temperature and time of brazing. The repeatability of experiment results is very good. With the help of the microscope, the diamond distributions on the filler metal are observed, and the surface and section of the brazing sample are observed carefully using SEM. EDS gives the existent elements and the content distributions of element in small area after brazing. XRD gives the existent phases of substance in filler metal and diamond. The experiments show that: the element of Fe in Ni-Fe alloy diffuses to the diamond surface and reacts with C in diamond so as to form a thin layer of carbide Fe₅C₂ at the interface between diamond and the filler metal. Because of the carbide, the brazing joining is realized between diamond and the steel substrate. From the wetting theory of liquid to solid and the theory of dissolving and diffusing, we can conclude further that: diamond dissolves into the filler metal and the filler metal diffuses to diamond, which forms the carbide. The carbide ameliorates the wetting of the filler metal to diamond, promotes the brazing ability of the filler metal to diamond.更多还原