精加工表面的分形特征研究

Research on the fractal behavior of fine machined surface

利用触针式轮廓仪和数据采集系统对精车和平磨加工表面的轮廓曲线进行了测量， 并基于分形几何理论， 分析和讨论了不同工艺参数对表面分形维数 Ｄ 和轮廓算术平均偏差 Ｒａ 的影响。研究结果表明， Ｄ 与 Ｒａ 反映了表面质量的不同侧面， 它们之间有一定的对应关系， 但并不是线性的；对于同种材料， 磨削加工的 Ｄ 值比车削时要大； 对于同种加工方法， 碳钢材料的 Ｄ 值比铸铁要大； 分形维数有可能揭示材料的可加工性。

Fractal geometry is a new method recently developed to describe the irregularities. The profiles of plane ground surfaces and fine turned surface were obtained by a Tarlysurf-10 contact stylus profiler, and the influence of various processing parameters on the fractal dimension D and the arithmetical mean deviation of profile Ra were investigated and discussed. The results show that fractal dimension D and Ra represent the different performance of surface, which don't exist the linear corresponding relation each other. For the same kind of material, the D of ground surface is bigger than that of fine turned surface. With the same working method, the D of steel componert surface is bigger than that of cast iron component surface. It is possible to reveal the machinability of material by fractal dimension.