研究了超精密车削表面微观拓扑形貌与光散射特性之间的关系,用于评价车削加工表面的光学性能并优化加工过程.采用阈值分析和粗糙表面散射理论分析两种方法研究了仅有理想刀痕的表面所产生的重影现象.阈值分析是指先计算单段圆弧刀痕的散射特性,再根据周期性结构对光的调制性来求得被加工表面为镜面对刀尖圆弧半径和进给率(主轴每转的进给距离)选择的大约临界值要求.在入射光波长500 nm的情况下,当刀尖圆弧半径选择500 μm时,可以计算得出阈值进给率为19μm.粗糙度散射理论分析则是通过电场积分公式——Stratton-Chu公式进行更精确的计算.实验表明,对于超精密车削加工得到的表面,当从入射光的非镜面方向,尤其是一极大散射方向观察不到光强时,即可以认为加工出了镜面效果.%The relationship between the microscopic topology and the optical performance of Single Point Diamond Turning (SPDT) surfaces was discussed to optimize SPDT machining parameters and to evaluate the optical characteristics of diamond turned surfaces. For surface microscopic topology generated by an ideal tool, the phenomena of multiple image reflection was analyzed by both threshold analysis and surface scattering theory analysis. With the threshold analysis, the scattering of single arc tool mark was calculated firstly, and then the modulation characteristics of periodic tool mark structure to the light was used to calculate the approximate thresholds of tool nose radius and feedrate (feeding distance per spindle rotation). In the situation of wavelength of incident light at 500 nm, the threshold feedrate is calculated to be 19 μm when the tool nose radius is 500 μm. With the roughness scattering theory analysis, the calculation could be more precise by using electric integral--Stratton-Chu Integral. Obtained results show that for a fine machined surface, when the light can not be seen in observing the turned surface with non-mirror direction, especially 1-order maximum direction, the surface can be recognized as a mirror effect.
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