Pang Qilong, Shu Zihao, Xu Youlin
College of Mechatronics Engineering, Nanjing Forestry University, Nanjing 210037, China.
Jiangsu Institute of Quality and Standardization, Nanjing 210029, China.
Materials (Basel). 2022 Nov 3;15(21):7759. doi: 10.3390/ma15217759.
To comprehensively analyze the effect of cutting parameters on the 3D surface topography of machined potassium dihydrogen phosphate crystals, 2D power spectrum density and continuous wavelet transform are used to extract and reconstruct the arbitrary actual 3D frequency features of machined potassium dihydrogen phosphate crystal surfaces. The 2D power spectrum density method is used to quantitatively describe the 3D surface topography of machined potassium dihydrogen phosphate crystals. The continuous wavelet transform method is applied to extract and reconstruct 3D topographies of arbitrary actual spatial frequency features in machined surfaces. The main spatial frequency features of the machined surfaces are 0.0056 μm, 0.0112 μm, and 0.0277 μm with the cutting depth from 3 μm to 9 μm. With the feed rate changing from 8μm/r to 18 μm/r, the main spatial frequency features are 0.0056 μm-0.0277 μm. With the spindle speed from 1300 r/min to 1500 r/min, the main spatial frequency features are same as the main spatial frequency features of the cutting depths. The results indicate that the variation of cutting parameters affects the main spatial frequency features on the 3D surface topography. The amplitudes of the spatial middle-frequency features are increased with the increasing of cutting depth and spindle speed. The spatial low-frequency features are mainly affected via the feed rate. The spatial high-frequency features are related to the measurement noise and material properties of potassium dihydrogen phosphate. The distributional directions of the frequency features in the reconstructed 3D surface topography are consistent with the distribution directions of actual frequency features in the original surface topography. The reconstructed topographies of the spatial frequency features with maximum power spectrum density are the most similar to the original 3D surfaces. In this machining, the best 3D surface topography of the machined KDP crystals is obtained with a cutting depth = 3 μm, feed rate = 8 μm/r and a spindle speed = 1400 r/min.
为全面分析切削参数对加工磷酸二氢钾晶体三维表面形貌的影响，采用二维功率谱密度和连续小波变换来提取和重构加工后磷酸二氢钾晶体表面任意实际三维频率特征。二维功率谱密度法用于定量描述加工后磷酸二氢钾晶体的三维表面形貌。连续小波变换法用于提取和重构加工表面任意实际空间频率特征的三维形貌。当切削深度从3μm变化到9μm时，加工表面的主要空间频率特征为0.0056μm、0.0112μm和0.0277μm。当进给速度从8μm/r变化到18μm/r时，主要空间频率特征为0.0056μm - 0.0277μm。当主轴转速从1300r/min变化到1500r/min时，主要空间频率特征与切削深度的主要空间频率特征相同。结果表明，切削参数的变化会影响三维表面形貌上的主要空间频率特征。空间中频特征的幅值随着切削深度和主轴转速的增加而增大。空间低频特征主要受进给速度的影响。空间高频特征与测量噪声和磷酸二氢钾的材料特性有关。重构三维表面形貌中频率特征的分布方向与原始表面形貌中实际频率特征的分布方向一致。具有最大功率谱密度的空间频率特征的重构形貌与原始三维表面最相似。在该加工过程中，当切削深度 = 3μm、进给速度 = 8μm/r和主轴转速 = 1400r/min时，可获得加工磷酸二氢钾晶体的最佳三维表面形貌。
