钛合金介观尺度铣削表面粗糙度特征分析及工艺优化

Surface morphology analysis and process optimization in micro-milling of titanium alloy

为提高钛合金介观尺度铣削加工表面质量,以主轴转速、每齿进给量、轴向切削深度为主要研究因素,对介观尺度铣削表面粗糙度特征进行了分析,优化了工艺参数。考虑到介观尺度铣削加工的间断性切屑形成和单齿切削现象,分析了刀具转角与切削厚度及累计弹塑性变形次数的对应关系。在此基础上,设计了正交实验,将铣削表面划分为逆铣区域、中间区域和顺铣区域,通过方差分析确认每齿进给量是介观尺度铣削表面粗糙度最重要的影响因素。采用田口方法分别对局部区域加工工艺参数进行优化。实验结果表明,相对于中间区域,逆铣区域和顺铣区域弹塑性变形更频繁,表面粗糙度更高,以逆铣区域或顺铣区域表面粗糙度为优化目标时的优化效果更好。

To improve surface quality in micro-milling of titanium alloy,the characteristics of milled surface in micro-milling was analyzed by taking spindle speed,feed per tooth and axial depth as the influence factors,and the process parameters were optimized.Through considering the intermittent chip formation and single-edge cutting phenomenon in micro-milling,the relationships between tool rotation angle,cutting thickness and cumulative number of elastic-plastic deformation were analyzed.On this basis,the orthogonal experiments were designed,and the milled surface was divided into up milling area,middle milling area and down milling area.ANOVA results showed that feed per tooth was the most obvious factors in micro-milling of titanium alloy.Milling parameters of each area were optimized by using Taguchi method.Experimental results showed that the surface roughness of up milling and down milling areas was higher than middle area,and the surface roughness in up milling area or down milling area should be used as the optimization objective for better optimization effect.