钛合金曲面超声辅助磁性磨料光整加工材料去除规律及去除函数

目的研究工件曲率半径、驻留时间以及加工角度对钛合金曲面超声辅助磁性磨料光整加工材料去除深度和材料去除曲线偏置程度的影响,建立不同走刀方式下的材料去除函数。方法在不同工件曲率半径、驻留时间和加工角度下,对钛合金曲面工件进行单点抛光试验,利用方差分析法,研究各因素水平对材料去除深度及材料去除曲线偏置程度的影响规律,采用最小二乘法拟合材料去除点坑在xoz平面和yoz平面内的材料去除曲线,基于二次多项式逐步回归方法,构建不同加工工艺参数下,材料去除曲线函数系数与加工工艺参数间的函数表达式,建立不同走刀方式下的材料去除函数,并对其进行准确性检验。结果由材料去除深度方差分析可得:驻留时间的F值为8.06,加工角度的F值为2.296,材料去除深度随驻留时间和工件曲率半径的增加而增加,随加工角度的增大,先增加后减小。由材料去除曲线偏置程度方差分析可得:工件曲率半径的F值为2.176,加工角度的F值为7.647,材料去除曲线偏置程度随工件曲率半径的增大而减小,随驻留时间和加工角度的增加而增加。此外,拟合的材料去除函数相关系数值R^2在0.97~0.99范围内。结论驻留时间对材料去除深度的影响最显著,加工角度次之,工件曲率半径影响最小。加工角度对材料去除曲线的偏置程度影响最显著,工件曲率半径次之,驻留时间影响最小。材料去除函数拟合结果较为准确,能满足实际的加工要求。

Material Removal Rule and Removal Function for Ultrasonic Assisted Magnetic Abrasive Finishing of Titanium Alloy Curved Surface

The work aims to analyze the effect of the curvature radius of workpiece, dwell time and finishing angle on material removal depth and the offset degree of material removal curve in ultrasonic assisted magnetic abrasive finishing of titanium alloy curved surface and establish material removal functions for different tool paths. Single point finishing experiments were carried out on titanium alloy curved surface under different curvature radius of workpieces, dwell time and finishing angles. The variance analysis method was used to analyze the influence of various factors on material removal depth and the offset degree of material removal curve. The material removal curves of material removal pit in xoz plane and yoz plane were fitted by the least squares method. The function expressions between the coefficient of material removal curve functions under different finishing parameters and the parameters were constructed based on quadratic polynomial stepwise regression method, and the accuracy of the function expressions was assessed. From the variance analysis of material removal depth, the F value of dwell time was equal to 8.06 and the F value of finishing angle was 2.296. The material removal depth rose with the increase of dwell time and the curvature radius of workpiece, and increased in the beginning and then decreased as the finishing angle enlarged. From the variance analysis of the offset degree of material removal curve, the F value of curvature radius of workpiece was equal to 2.176 and the F value of finishing angle was 7.647. The offset degree of material removal curve decreased as the curvature radius of workpiece increased, and rose with the increase of dwell time and finishing angle. In addition, the correlation coefficient value R2 of the fitting material removal functions was in the range of 0.97 to 0.99. The dwell time has the most significant effect on the material removal depth, the secondary is finishing angle, and the last is the curvature radius of workpiece. The finishing angle has the most significant effect on the offset degree of material removal curve, the following is the curvature radius of workpiece, and the least is dwell time. The fitting result of material removal function is very accurate and can meet the actual finishing requirements.