高铁白车身拉丝加工表面纹理参数化评价方法

Parametric evaluation method of surface texture generated on high-speed rail body by brushing finish

针对拉丝加工表面纹理的获取缺乏材料微观去除层面的理论指导与量化评价指标的问题,提出一种面向铝合金高铁白车身拉丝表面纹理形成的参数化评价方法.选择磨粒的几何形状和尺寸、分布间距和出刃高度作为拉丝轮形貌特征评价参数,根据磨粒分层和随机分布规律在二次开发的拉丝轮参数化建模平台上自动生成拉丝轮模型,并确定以沿纹理方向的微观不平度十点高度和垂直纹理方向的轮廓微观不平度的平均间距作为特征参数区分直纹和雪花纹.仿真和实验结果表明:通过该方法可以获得理想的直纹和雪花纹,其中直纹的微观不平度十点高度小于2μm,轮廓微观不平度的平均间距大于0.2 mm,雪花纹的微观不平度十点高度大于5μm,轮廓微观不平度的平均间距小于0.1 mm.

Aiming at the problem that obtaining brushed surface texture lacks of theoretical guidance and quantitative evaluation indexes from the perspective of microscopic material removal,a parametric evaluation method for the surface texture generation of aluminum alloy high-speed rail body by brushing finish was proposed.The geometric shape and size,distribution spacing and protrusion height of the abrasive grains were selected as the evaluation parameters of the topography characteristics of the brushing wheel.According to the abrasive layering and random distribution rules,the brushing wheel model was automatically generated on the secondary developed parametric modeling platform.Both ten-point height of irregularities along the texture direction and the mean spacing of profile irregularities in the vertical texture direction were utilized as the characteristic parameters to distinguish the straight pattern and snow pattern.Simulation and experimental results show that the ideal straight and snow patterns can be obtained by this method,in which the ten-point height of irregularities and mean spacing of profile irregularities for the straight pattern are smaller than 2μm and greater than 0.2 mm,respectively,and the corresponding values for the snow pattern are greater than 5μm and smaller than 0.1 mm.