【作者】 铁晓锐；

【导师】 徐西鹏；

【作者基本信息】 华侨大学 ， 切削磨削工艺， 2012， 硕士

【摘要】 金刚石工具不仅被广泛应用于建筑业、石材加工业、汽车工业、交通工业、地勘与国防工业等传统领域，而且在宝石、医疗器械、木材、玻璃钢、石材工艺品、陶瓷和复合非金属硬脆材料等众多新领域也不断得到应用，且需求量正在逐年大幅增加。在不考虑其加工成本的前提下，针对如何提高金刚石加工工具的切削性能和使用寿命的研究就非常有意义。本文以石材加工中常用的烧结金刚石和钎焊金刚石为研究对象，以试验为主要研究手段，采用力学性能分析和利用SEM、XRD、XPS等界面微观分析方法，研究了钎焊金刚石工具和烧结金刚石工具制作过程中工艺、结合剂等对金刚石的组织形貌和性能的影响，并从微观角度来分析了它们之间的相互作用机制及两种金刚石工具磨削性能。本课题来源于国家杰出青年科学基金“切削、磨削加工工艺与装备”（50825505）。研究结果表明，稀土元素具有较强的还原能力，从而有效地提高了铜基金刚石节块的力学性能，强化了胎体材料对金刚石的把持能力。在结合剂中添加TiH2成分可以显著提高节块的抗弯强度和硬度，且TiH2成分对力学性能的影响超过了稀土元素，说明Ti元素无论是以化合物形式添加，还是作为镀层镀覆，都能对金刚石与胎体组织的粘结性起到良好的促进作用。Ni-Cr合金对金刚石表现出较好的浸润性和把持能力，钎焊金刚石工具在加工过程中，活性元素Cr与C原子发生了界面反应，形成了界面反应层，随后界面处发生了显著的相互扩散并形成新的稳定的碳化物“纽带”结构，它促进了两者之间的润湿结合，在一定程度上增强了金刚石工具的把持能力。烧结金刚石在垂直和水平两个方向受力较大，随后在一定区间内逐渐趋于平稳，而钎焊金刚石的受力逐渐增大且超过烧结金刚石。钎焊金刚石磨削过程中出露高度明显下降，随着加工时间和磨削次数的增加，出露高度变化趋于平稳；烧结金刚石经过多次磨削后出露高度变化不大，处于稳定状态。研究工作表明，本文通过微观测试手段，对金刚石磨粒与结合剂界面进行的微观分析、界面之间的生成物及其结构、状态、产生环境以及它们对金刚石结合强度的影响机制等研究内容，将对减少金刚石磨粒的非正常失效、开发新型高结合强度的金刚石工具有着较为重要的学术意义和工程应用价值。更多还原

【Abstract】 Diamond tools are not only widely applied in the traditional areas, such as construction, stone material manufacturing, automobile industry, transportation, geological survey and defense industries, but also used in the new areas of the jewelry, medical instrument, timber, glass fiber reinforced plastics, stone handicraft, ceramics and composite non-meta hard and brittle materials. The demand of diamond tool is largely increasing annually. Considering without increase of manufacturing cost, the studies that aim to improve the cutting performance and service life of the diamond tools is significant and necessary.Results show that the rare earth element has relatively strong redox capacity, which effectively improves the mechanical properties of cupper based diamond segment, and reinforces the control of matrix material on diamond. The addition of TiH2in the matrix can significantly improve the bending strength and hardness of the segment, and the influence of TiH2component on mechanical properties exceed that of the the rare earth element, indicating titanium element, whether if form of compound or as coating, can promote the bonding of diamond and matrixNi-Cr alloy shows good infiltration and holding on the diamond abrasive. In the process of the brazed diamond tool, the active element of Cr and C atoms react at the interface, and form the reaction layer, consequently the obvious diffusion happened at the interface and form the new stable bind structure of carbide, promoting the infiltration between each other, to enhance the control of diamond tool to certain extent.The forces with the sintered diamond tool are relatively large along the vertical and horizontal directions, and then are gradually prone to be stable in certain range. However, the forces with the brazed diamond tool gradually increase and exceed that of the sintering diamond tool. The protrusion height of the brazed diamond tool significantly decrease during its grinding process, and the height varies and stabilize, along with the grinding process; while for the sintered diamond tool, the protrusion height change little after multiple grindings and keep stable.Based on the microscopic experiments, this thesis discusses the product of interface between the diamond grit and matrix and its structure, state and formation environment, along with the influence mechanisms of these factors on the diamond bond strength. The results will shed light on the science and engineering practice of reducing unusual failure of the diamond grits and developing new diamond tool with high bond strength.更多还原