磨削对氧化膜去除质量影响的稳定性与敏感性

目的研究磨削参数对电化学加工氧化膜去除质量的影响规律,以及各参数对氧化膜去除质量影响的稳定性和敏感性。方法在试件表面形成均匀一致,无缺陷电化学加工氧化膜的前提下,借助自主搭建的机械磨削实验平台,分别研究磨粒尺寸、工件速度、磨削压强和加工时间对氧化膜去除质量的影响,使用精密电子天平和扫描电子显微镜对实验前后的试件进行测量,结合稳定性与敏感性分析理论对实验结果进行分析。结果不同的加工参数对氧化膜去除程度的影响不尽相同,氧化膜既存在不完全去除的现象,也存在完全去除的现象。扫描电子显微镜结果也显示,不同尺寸的磨粒对氧化膜的破坏程度不同,其表面氧化膜的沟槽深浅不同。结论受氧化膜硬度低、容易去除和基体金属硬度高、不容易去除的影响,氧化膜去除质量随着工件速度和加工时间的增加呈现三次曲线的规律增加,随磨削压强和磨粒尺寸的增大呈线性增加趋势。磨削参数对氧化膜去除质量影响的稳定性与敏感性不同,而且在电化学机械加工生产应用中不改变磨削工具,所以在磨削参数相对值较低的区间,其对去除质量影响的稳定性由大到小(敏感性由小到大)为:磨粒尺寸、加工时间、磨削压强、工件速度。在磨削参数相对值较高的区间,稳定性由大到小(敏感性由小到大)为:磨粒尺寸、磨削压强、工件速度、加工时间。加工中优先选择稳定性高(敏感性低)的参数作为调整电化学机械加工效果的主要因素,可在提升经济性的同时,提高加工精度。

Effect of Grinding on the Stability and Sensitivity of Oxide Film Removal Quality

The work aims to study the effect of grinding parameters on the removal quality of oxide film by electrochemical machining (ECM) and the stability and sensitivity of each parameter to the removal quality of oxide film. When the surface of specimen was formed with a uniform, defect-free oxide film, the self-built mechanical grinding experiment platform was used to study the grit size, workpiece speed, grinding pressure and processing time on the removal quality of oxide film. The precision electronic balance and SEM were used to measure the specimens before and after experiment. The experimental results were analyzed according to the analysis theory of stability and sensitivity. Different grinding parameters had different effects on the removal degree of oxide film, so both incompletely and completely removed oxide films existed on the surface of specimen. From SEM results, different grit size and grinding pressure caused different damage to oxide film, so the depth of groove on the oxide film was also different. Effected by the low hardness of oxide film easy to be removed and the high hardness of basic metal hard to be removed, the removal quality of oxide film increases in cubic curve as the workpiece speed and processing time rise. However, the removal quality of oxide film increases linearly as the grinding pressure and grit size rise. The stability and sensitivity to effect of grinding parameters on oxide film are different and the grinding tool is not changed in electrochemical mechanical production. Therefore, in the lower range of grinding parameters, the stability of its effect on oxide film from high to low (sensitivity from low to high) is: processing time, grit size, grinding pressure and workpiece speed. In the higher range of grinding parameters, the stability of its effect on oxide film from high to low (sensitivity from low to high) is: grinding pressure, workpiece speed, processing time and grit size. In electrochemical mechanical machining, the high stability (low sensitivity) is preferred as the main factor to adjust the machining effects and improve machining accuracy with the increasing of economical efficiency.