钛合金金刚石砂带精密磨削磨粒磨损机理及抑制方法研究

With the comprehensive requirements have increased markedly for precision grinding of the key functional parts made up of titanium alloy in aeroengine, which includes the intelligent manufacturing and the consistency of machining accuracy and surface quality, the ordinary abrasive belts are difficult to meet the processing demand due to the lack of service life. Diamond abrasive belt has been widely used in precision machining of hard brittle materials and nonferrous metals owing to its excellent mechanical properties. However, the abrasive wear rate in grinding of titanium alloy by diamond abrasive belt is relatively high under normal conditions, which restricts its application in the field of precision grinding of titanium alloy. Aiming at solving the difficult problem of the serious diamond abrasive wear, the model of precision grinding of titanium alloy by diamond abrasive belt will be established, for revealing the influence mechanism of the interaction between diamond grains and workpiece on the abrasive wear under the flexible contact state. Subsequently, the frictional wear behavior and tribochemical reaction characteristics of diamond grains with workpiece materials in thermal and mechanical joint excitation will be investigated, in order to reveal the abrasive wear mechanism under the action of thermo-mechanical coupling and establish the prediction model of abrasive wear. On the basis of the research mentioned above, the effective suppression method of diamond abrasive wear will be proposed for achieving the optimum processing technology of precision grinding of titanium alloy by diamond abrasive belt. The research results will expand the application fields of diamond abrasive belt precision grinding. Additionally, it holds great theoretical significance and application value for improving the processing capacity of the titanium alloy blisk and blade of aviation engine in our country.

随着航空发动机钛合金制成关键功能零部件精密磨削过程中加工精度、表面质量的一致性以及智能化制造综合要求的日趋苛刻，普通磨料砂带由于使用寿命不足已难以满足加工需求。金刚石砂带因其具有优异的机械力学性能而广泛应用于硬脆材料和有色金属的精密磨削，但常规条件下磨削钛合金时磨粒磨损速率较高，制约了其在钛合金精密磨削领域的应用。本项目针对金刚石磨粒磨损严重的难题，提出建立钛合金金刚石砂带精密磨削模型，揭示柔性接触状态下磨粒-工件交互作用对磨粒磨损的影响机制；研究金刚石磨粒与工件材料在热能和机械能共同激发下的摩擦磨损行为及摩擦化学反应特征，揭示热力耦合作用下金刚石砂带磨粒磨损机理并建立相应的预测模型；提出磨粒磨损的有效抑制方法，获得实现钛合金金刚石砂带精密磨削加工的最优工艺。研究成果将扩大金刚石砂带精密磨削的应用领域，对提高我国航空发动机钛合金整体叶盘、叶片的加工能力与水平具有重要的理论意义和应用价值。

随着航空发动机钛合金制成关键功能零部件精密磨削过程中加工精度、表面质量及一致性等智能化制造综合要求的日趋苛刻，普通磨料砂带因使用寿命不足已难以满足加工需求。金刚石砂带因其具有优异的机械力学性能而广泛应用于硬脆材料和有色金属的精密与超精密磨削，但常规条件下磨削钛合金时磨粒磨损速率较高，制约了其在钛合金精密磨削领域的应用。本项目针对金刚石砂带磨损严重的难题，研究了金刚石砂带的结构形式和磨粒分布规律，采用基于快速傅里叶变换的二维数字滤波技术实现了砂带表面形貌的生成，并实现了钛合金工件磨削表面形貌的精准预测，进而建立了钛合金金刚石砂带材料去除模型；研究了复杂型面加工中砂带-工件的接触形态，建立了接触状态有限元仿真模型，揭示了柔性接触状态下磨粒-工件交互作用对磨粒磨损的影响机制；研究了金刚石磨粒与工件材料在热能和机械能共同激发下的摩擦磨损行为及摩擦化学反应特征，揭示了热力耦合作用下金刚石砂带磨粒磨损机理，建立了单颗金刚石磨粒和金刚石砂带磨损的预测模型；提出了基于微量润滑技术的金刚石砂带磨损抑制方法，进行了不同润滑条件下的对比磨削试验，验证了微量润滑技术对金刚石砂带磨损抑制的可行性；采用参数化控制方法获得了实现钛合金金刚石砂带精密磨削加工的最优工艺，进而开展了某型号航空发动机钛合金叶片金刚石砂带磨削实验研究，磨削后叶片型面精度、表面质量均达到要求。综上所述，该研究成果对扩大金刚石砂带精密磨削的应用领域、提高我国航空发动机钛合金整体叶盘、叶片的加工能力与水平具有重要的理论意义和应用价值。