基于多波长散射光特性的铝合金超精密车削表面粗糙度测量方法研究

针对超精密车削表面，提出一种基于多波长散射光特性的表面粗糙度测量方法，以铝合金为例对该方法进行验证。首先建立超精密车削表面形貌—散射光模型并开展验证实验，定量实验结果证明建立的散射光模型平均误差仅为1%。基于散射光模型研究刀痕纹理方向、刀痕宽度(每转进给量)和刀痕高度(表面粗糙度峰谷值)对镜像光反射率的影响，研究结果证明表面粗糙度是影响镜像光反射率的关键因素。在此基础上进一步建立300～700 nm波长范围内镜像光反射率平均值和表面粗糙度之间的定量关系，基于超精密车削表面的测量结果对该定量关系进行验证。所提出新方法获得的粗糙度测量结果与原子力显微镜测量结果吻合，最大相对误差仅为7.5%。

Investigation on Measurement Method of Ultra-precision Turning Surface Roughness Based on Multi-wavelength Scattering Characteristic

For ultra-precision turning surface, a surface roughness measurement method based on a multi-wavelength scattering characteristic is proposed, which is further validated with an aluminum alloy material. First, a theoretical model of surface topography-light scattering for ultra-precision turning surface are established. A validation experiment is performed. Quantitative experimental results show that the average error of the scattering model is only 1%. Based on this scattering model, the influence of turning mark direction, turning mark width (feed rate per revolution), and turning mark height (peak-valley surface roughness) on the specular reflectivity is studied. Investigation results show that surface roughness is the critical influencing factor of specular reflectivity. On this basis, the quantitative relationship between average specular reflectivity from 300 to 700 nm and surface roughness is established, which is validated based on the ultra-precision diamond turning experiment results. The surface roughness results achieved by the newly developed method is consistent with the results measured by atomic force microscope (AFM). The maximum relative error is only 7.5%.