容器尺寸对叶片竖直强制振动光整加工效果的影响

Influence of Container Size on Processing Effect of Vertical Forced Vibration Finishing for Blades

为实现航发叶片的均匀一致性高效光整,探究竖直强制振动光整加工工艺中容器尺寸对叶片加工效果的影响。以正四棱柱容器的高度、宽度、长度作为变量,基于离散元法,对不同尺寸参数下颗粒介质对叶片表面的力学行为及加工效果进行分析,确定较优的容器尺寸参数,并通过接触力测试分析和加工试验验证模拟的有效性。结果表明:叶片安装位置相对不变时,容器尺寸直接影响叶片的加工效果;容器高度对叶片加工效果影响程度最为明显,随着容器高度的增加,叶片表面所受法向力增大,叶片与颗粒介质间的相对速度增大,加工效率变高,加工均匀性变好;随着容器宽度的增加,加工效率先提高后降低,均匀性逐渐变差;随着容器长度的增加,加工效率降低,均匀性变好;当容器的高度为300 mm、宽度为120 mm、长度为200 mm时,加工效果较优;采用该工艺参数对试件加工后,表面粗糙度由0.645μm下降至0.246μm,表面轮廓相对平整,铣削痕迹明显去除。研究成果可为滚磨光整加工中容器尺寸的优选提供数据支持。

A compressor blade is a key component of an aero-engine often in a high-speed,high-temperature,and high-pressure environment.After milling,there are surface defects such as milling cutter marks and microcracks on the surface of the blade.The surface quality after milling cannot meet quality requirements,therefore the final working surface must undergo surface finishing.In this paper,the surface finishing of the blade is realized by the vertical forced vibration finishing process.At present,research on the relationship between excitation parameters and the behavior of granular media is relatively advanced,yet few scholars have studied the influence of container size on the behavior of granular media.In order to explore the influence of container size on the finishing effect of compressor blades,the dimensions of the regular prismatic container were taken as variables,and based on the discrete element method,the change in the mechanical behavior of granular media on blades and the change in the processing effect for different container size parameters were analyzed.Subsequently,optimum container size parameters were determined.The effectiveness of the simulation was verified via contact force test analysis and processing tests.Results show that when the installation position of the blade is relatively unchanged,during the vibration process,the mechanical behavior of the granular media on the blade is affected by the size of the container,which in turn affects the processing effect of the blade.The height of the container has the most obvious influence on the processing effect of the blade.As the height of the container increases,the contact force on the blade surface increases,the relative velocity between the blade surface and the granular media increases,the processing efficiency increases,and thus processing is more uniform.The container width has the second greatest effect on the machining effect of the blade.As the width of the container increases,the contact force on the blade surface gradually decreases,the relative velocity between the blade surface and the granular media initially increases before decreasing,the processing efficiency initially increases before decreasing,and the uniformity gradually deteriorates.The length of the container has the least influence on the processing effect.As the length of the container increases,the contact force on the blade surface gradually decreases,the relative velocity between the blade surface and the granular media initially increases before decreasing,the processing efficiency decreases,and the uniformity deteriorates.After a comparative analysis,the optimum container size parameters were determined;when the height of the container was 300 mm,the width was 120 mm,and the length was 200 mm,the processing effect was optimal.After the optimum container size parameters were used to process the specimen,the surface roughness was reduced from 0.645μm to 0.246μm,reaching the surface roughness industrial requirements for an aero-engine blade.The surface profile was relatively flat,and the milling marks were removed.Moreover,a preliminary understanding of the influence of container size on the motion behavior of granular media under vertical vibration was obtained,providing a theoretical basis for the optimization of container size in barrel finishing processing.