局部感应钎焊单层CBN成型砂轮及其磨削性能研究

The brazed monolayer super-abrasive grinding wheels, which are regarded as the new generation tools related to the electro-plated grinding wheels, are the crucial tools for the high efficiency deep grinding (HEDG) of difficult-to-machine materials. However, the temperature field is un-uniformity during induction brazing of complex profiled grinding wheels, leading to the fact that the performance the brazed grinding wheels can’t meet the needs of HEDG. In order to solving this pivotal problem, local induction brazing of monolayer CBN profiled grinding wheels is proposed based on controlling the transformation and transmission among electric energy, magnetic energy and thermal energy in induction heating. Firstly, local induction heating of profiled surface energy transformation model is established. Local induction heating temperature control strategy is presented. Next, thermal stress-strain coupling relation of the wheel during local induction brazing is investigated. The thermal elastoplastic deformation rule of the wheel is revealed. Then, interface formation mechanism and wear mechanism of the newly brazed wheel are illuminated, and wear control stratagem is put forward. Finally, the high accuracy, high sharpness and high durability profiled monolayer brazed CBN grinding wheel is developed successfully. The research achievement of this project can break through the technical bottlenecks of improving the processing efficiency of HEDG, and have significant theory and engineering value for promoting the application of difficult-to-machine materials such as Ni-based superalloys in the field of aviation.

单层钎焊超硬磨料砂轮被认为是当前电镀砂轮的最佳换代产品，是难加工材料高效深切磨削的关键工具保障。针对复杂轮廓成型砂轮感应钎焊存在的温度不均匀问题，导致单层钎焊超硬磨料砂轮难以满足高效深切磨削对砂轮性能要求的现状，本项目基于成型砂轮工作层电-磁-热能转换与传递的主动调控，提出局部感应钎焊单层CBN成型砂轮的研制构想。首先，建立成型面局部感应加热的能量传递模型，提出局部感应加热的温度调控策略；再研究砂轮基体热应力-应变耦合关系，揭示其热弹塑性变形规律；然后阐明单层CBN成型砂轮的界面形成机理与磨损机理，提出合理的砂轮磨损抑制策略，最终研制集高精度、高锋利度、高耐用度于一体的单层钎焊CBN成型砂轮。项目成果对于突破高效深切磨削发展的技术瓶颈，推动镍基高温合金等难加工材料在航空领域的应用具有重要的理论意义和实用价值。

单层钎焊立方氮化硼（CBN）砂轮具有磨削力小、加工效率高等优点，在航空航天等领域的关键零部件成型磨削加工中具有广阔的应用前景。针对复杂轮廓成型砂轮感应钎焊温度不均匀的问题，本项目基于成型砂轮工作层电-磁-热能转换与传递主动调控的思路，提出局部感应钎焊单层CBN成型砂轮的研制构想。主要开展的研究内容包括：.（1）建立了成型面局部感应加热的有限元模型，研究了特征成型面的温度分布规律，基于成型面温度均匀性的评价模型，探索了成型面局部感应钎焊过程中的能量传递机理，分析了温度均匀性的影响因素及其交互机制。.（2）建立了砂轮基体局部感应钎焊的多场耦合有限元模型，提出了热源简化方法，研究了局部感应钎焊过程中热源功率、扫描速度等因素对砂轮基体组织演变、应力分布、变形量的影响规律，揭示了砂轮基体变形的机理。.（3）研制了单层钎焊CBN成型砂轮，分析了钎料/CBN磨粒界面特征及其形成机理，通过与单层电镀CBN成型砂轮对比试验研究了新型钎焊CBN砂轮的磨削性能，分析了磨削工艺参数对TC4钛合金型槽加工精度、表面质量的影响规律，揭示了砂轮的磨损机理。.项目完成了预期的研究目标，研究成果为突破高效深切磨削发展的技术瓶颈、推动钛合金等难加工材料在航空领域的应用提供了重要的理论基础。