金属陶瓷超精密磨削表面创成机制及控制方法研究

To meet the requirement of the high-efficiency and precision production of cermet components in the civilian and national defense fields, this project investigates the surface formation mechanism and the controlling techniques of WC/Co and Ti(C,N)/Ni under ultra-precision grinding by the brazed diamond wheels of arraying patterns after precision dressing by the pulsed laser. Based on the investigation of the material removal and surface damage mechanism of the cermets by theoretical analysis and experimental study, the brazed diamond wheels of arraying patterns are firstly designed and fabricated based on the critical depth of cut for the ductile to brittle transformation and the maximum undeformed chip thickness. The pulsed laser dressing method is then applied to improve the efficiency and to prevent the grinding ability dropping of the wheel by the existing dressing process. After establishing the relationship mapping between the ground surface integrity and the machining parameters, the arraying patterns of the diamond grains and the dressing schemes of the wheel, the controlling techniques of the surface integrity is finally proposed by optimizing the arraying patterns of the diamond grains, improving the dressing scheme and choosing the right machining parameters. This research can provide the theoretical and technical support for the improvement of the production efficiency and surface quality of cermets and other hard materials by ultra-precision grinding and promote the wider application of the brazed diamond wheel with arraying patterns.

针对民用和国防领域对金属陶瓷元件高效率和高精度的生产需求，本项目以WC/Co和Ti(C,N)/Ni为研究对象，开展基于脉冲激光修整磨粒有序排布钎焊金刚石砂轮的金属陶瓷超精密磨削技术研究。在应用理论分析与基础试验揭示金属陶瓷磨削表面材料去除机理及损伤机制的基础上，基于材料脆-塑转变临界条件及磨粒最大未变形切屑厚度设计并制备磨粒有序排布钎焊金刚石砂轮，采用脉冲激光修整解决现有钎焊金刚石砂轮修整方法效率低及修整后磨削能力变差的问题，建立磨削加工参数、磨粒排布方式及砂轮修整方案与表面完整性参数之间的映射关系，实现通过优化钎焊砂轮磨粒排布方式、调控脉冲激光修整策略、合理选择磨削工艺参数控制加工表面质量的目的。本项目的研究将为提升金属陶瓷及其他硬脆材料的超精密加工效率、降低表面损伤以及拓宽磨粒有序排布钎焊金刚石砂轮在超精密磨削加工中的应用提供理论与技术支撑。

针对民用和国防领域对金属陶瓷元件高效率和高精度的生产需求，本项目开展了金属陶瓷超精密磨削表面创成机制及控制方法研究，主要内容包括金属陶瓷磨削材料去除机制、金刚石脉冲激光烧蚀机理、钎焊金刚石砂轮脉冲激光修整、金属陶瓷精密磨削工艺优化四个方面，取得的主要创新研究成果如下： .（1）揭示了金属陶瓷（WC/Co和TiC/Ni）材料去除机理及损伤机制，阐明了脉冲激光烧蚀金刚石轮廓演变规律，获得了脉冲激光参数与能量分布和烧蚀轮廓的对应关系。.（2）建立了基于砂轮表面地貌的磨削表面形貌仿真和磨削力预测模型，揭示了织构化磨粒的磨损机制，阐明了磨粒排布及织构化参数对磨削表面特征的影响规律，优化设计了磨粒有序排布钎焊金刚石砂轮参数。.（3）提出了基于全域采集-图像处理的超硬磨料砂轮磨粒等高性评价方法，优选了钎焊金刚石砂轮脉冲激光织构化加工路线策略，实现了面向不同工艺的钎焊金刚石砂轮表面织构高效精密创制。.（4）试验验证并评价了磨粒织构化钎焊金刚石砂轮的加工性能，通过优化钎焊金刚石砂轮的磨粒排布方式、调控砂轮修整方案、合理选择磨削工艺参数，实现了WC/Co硬质合金的高效率超精密加工及表面完整性的控制。. 该项目通过开展基于脉冲激光修整磨粒有序排布钎焊金刚石砂轮的金属陶瓷超精密磨削技术研究，完成了金属陶瓷材料的超精密磨削并提高加工效率、降低表面损伤的目标，并为进一步拓宽磨粒有序排布钎焊金刚石砂轮在硬脆材料超精密磨削加工中的应用提供了理论与技术支撑。