超声微铣削加工毛刺成形特性研究

为减少微细切削加工过程中产生的微型毛刺对微型零件成形加工质量的影响，利用双直槽结构矩形六面体超声变幅器对工件施加水平辅助超声振动，在304奥氏体不锈钢板表面进行微沟槽结构超声微铣削成形加工试验，研究不同超声微铣削参数条件下铣削顶部毛刺的成形特性.试验结果表明，工件的水平超声振动使得不锈钢微沟槽顶部毛刺形态由长条形的絮状结构变为连续的片状结构；且随着超声振幅的增大，片状毛刺的高度逐渐减小，呈微细碎片化趋势.工件的水平超声振动还有利于减小微铣削沟槽顶部毛刺的长度，且当每齿进给量略大于刀具最小切削厚度时，毛刺长度的减小最为明显. 

Research on the Burr Forming Characteristics of Ultrasonic Assisted Micro-Milling Process

Tiny burrs are the key influence factors on the forming quality of micro parts,which are generated in the micro cutting process.In this paper,a horizontal ultrasonic vibration was superimposed on workpiece by double-slotted rectangular hexahedron sonotrode.The ultrasonic micro milling experiments with horizontal workpiece vibration were applied to machine micro grooves on 304 Austenitic Stainless steel sheets and the burr forming characteristics of ultrasonic micro milling process with different experimental parameters was studied.The experimental results show that the horizontal ultrasonic vibration of workpiece can change the burr shape from elongated flocculent structure to continuous flake structure,which is located on the top of micro grooves.With the increasing of ultrasonic vibration amplitude,the height of flake burr decreases gradually and turns into tiny fragments.On the other hand,the horizontal ultrasonic vibration of workpiece can also be helpful to reduce the burr length of micro milling groove. When the tooth feed rate of micro-milling cutter is slightly larger than its minimum cutting thickness,the decrease of burr length will be the most obvious.