超声辅助磨削SiC陶瓷单颗磨粒切厚的多元协同控制研究

In order to improve unstable machining quality due to poor controllability of undeformed chip thickness during ultrasonic assisted grinding (UAG) of advanced ceramics, a new research method was proposed to control this parameter on the basis of ductile-regime grinding theory. Specifically, the control method was fulfilled by synergy effect of optimizing grain distribution parameters, strengthening vibration stability of grinding wheel and optimizing matching performance of vibration parameters and grinding parameters. Taking SiC ceramics as the research object, effect of ultrasonic vibration on critical-depth-of-cut for its brittle-ductile transition was revealed firstly. Based on this work, optimizing of grain distribution was conducted aiming at grains trajectories overlapping area. Then undeformed chip thickness model during UAG was established. Meanwhile, optimization design of grinding wheel body on material and structure were executed on the basis of vibration energy loss analysis of vibration system. Following, the grinding wheel possesses defined grain distribution suitable to UAG was prepared. In addition, a model between critical grinding parameters and grains trajectories overlapping area was built. Based on this model, matching performance of grinding and vibration parameters was optimized. Finally, multivariate cooperative control of undeformed chip thickness was realized. The project research results have great theoretical significance to produce further advantages for UAG and promote ductile-regime grinding of advanced ceramics.

针对目前超声辅助磨削先进陶瓷时单颗磨粒切厚可控性差，以及由此引起的加工质量不稳定的问题，基于延性域磨削理论，提出通过优化超声辅助磨削砂轮工作层磨粒排布参数、强化砂轮振动性能稳定性、优化磨削用量与超声振动参数匹配性三方面协同作用，实现对超声辅助磨削单颗磨粒切厚控制的研究构想。选取SiC陶瓷为研究对象，在揭示超声振动作用对其脆-延转变临界切厚影响规律的基础上，以砂轮工作层磨粒运动轨迹重叠面积为目标优化磨粒排布并建立单颗磨粒切厚模型，同时基于系统超声振动能量损耗分析优选基体材料、设计基体结构，进而制备出适应于超声辅助磨削的磨粒有序排布砂轮，建立临界磨削用量-磨粒运动轨迹重叠面积模型，开展振动参数与磨削用量的匹配性优化，最终实现单颗磨粒切厚的多元协同控制。项目研究成果对于进一步发挥先进陶瓷超声辅助磨削优势、推动先进陶瓷延性域磨削技术的发展具有重要的理论意义。

针对目前超声辅助磨削先进陶瓷时单颗磨粒切厚可控性差，以及由此引起的加工质量不稳定的问题，基于延性域磨削理论,提出了单颗磨粒切厚多元协同控制思想的超声辅助磨削SiC陶瓷方法。主要开展的研究内容包括：.（1）基于单颗磨粒超声辅助磨削试验，采用连续变切深方法，通过单颗磨粒磨削划痕微观形貌观测，分析了随磨削深度变化材料去除时脆-延去除机理的转变过程，研究了超声振动作用对SiC陶瓷脆-延转变临界切厚的影响规律。.（2）开展了超声辅助磨削运动学分析，在此基础上提出了适应于超声辅助磨削运动学特征的砂轮工作层磨粒有序排布方案（磨粒周向间距Δx = 1.25 mm，排布角度β = 30°）；基于ANSYS模态分析研究了基体材料对砂轮振动性能的影响规律，对其结构形式及尺寸进行了优化设计；最终选用0Cr18Ni9作为基体材料，并采用钎焊技术制备了钎焊磨粒有序排布金刚石砂轮。.（3）采用上述制备的磨粒有序排布钎焊金刚石砂轮，同时以同规格的传统电镀砂轮作为对照开展了超声辅助磨削SiC陶瓷实验，结果表明相比于电镀砂轮，本研究研制的磨粒有序排布砂轮可有效改善磨削表面质量的均匀性，同时其振动参数与磨削用量具有更好的匹配性，即可在更大的磨削用量范围内发挥超声辅助磨削优势（磨削速度vs = 32 m/s时仍优于传统砂轮）。.（4）基于磨粒有序排布砂轮可实现单颗磨粒切厚均匀控制的这一基本原理，讨论了单颗磨粒切厚变化对材料去除机理、表面/亚表面损伤的影响规律，并通过磨削表面微观形貌特征、表面粗糙度等测量结果，评价了磨粒有序排布砂轮超声辅助磨削时单颗磨粒切厚的均一化程度，研究结果对进一步发挥先进陶瓷超声辅助磨削的优势具有重要的理论意义。.项目完成了计划书的研究内容，基本实现了预期研究目标。项目已发表研究论文11篇，授权发明专利1项、实用新型专利1项，公开发明专利2项，已培养/正在培养研究生4人。