基于NSGA-Ⅱ算法优化的SiC_(p)/Al复合材料超声磨削表面评价研究

Research on evaluation of machined surface in ultrasonic grinding of SiCp/Al composites based on NSGA-Ⅱ

碳化硅颗粒增强铝基复合材料(SiCp/Al)具有优异的机械物理性能,也是一种典型的难加工材料,加工表面易产生裂纹、凹坑等缺陷,使用表面粗糙度难以有效表征评价该类材料的表面加工质量。针对SiCp/Al复合材料加工表面质量表征评价困难的现状,文章提出了综合反映SiCp/Al复合材料已加工表面形貌特点的特征参数Scr的概念,并以其为优化目标,基于NSGA-Ⅱ算法对SiCp/Al复合材料超声振动磨削加工进行了工艺参数优化,获得了优化工艺参数组合为主轴转速n=15000 rpm、进给速度vf=5 mm/min、磨削深度ap=15μm、超声振幅A=5μm。对工艺参数优化方法的有效性进行了实验验证,结果表明,采用优化后的工艺参数提高了SiCp/Al复合材料的加工表面质量,特征粗糙度能够有效表征SiCp/Al复合材料的加工表面质量。

Silicon carbide particle reinforced aluminum matrix composite(SiCp/Al)possesses superior physical and mechani?cal properties such as high specific strength and specific stiffness,but it is one kind of typically hard to machine material,and the machined surface is prone to appearing cracks,pits and other defects,in addition,surface roughness can't effectively evaluate the surface processing quality of such materials.Aiming at this status,characteristic parameter Scr was put forward to comprehensively reflect the machined surface morphology of SiCp/Al Composite.Taking it as the optimization objective,the process parameters for ultrasonic vibration grinding of SiCp/Al composite were optimized based on NSGA?Ⅱ algorithm.Finally,the optimum conditions are as follows:spindle speed n=15000 r/m,feed rate vf=5 mm/min,cutting depth ap=15μm and vibration amplitude A=5μm.The optimization method of process parameters is verified by experiments,and the experimental results agree well with optimization results,characteristic roughness can effectively evaluate surface processing quality of SiCp/Al composites.