钛合金微槽超声螺线辅助铣磨加工试验研究

Experimental Research on Ultrasonic Spiral Assisted Milling and Grinding of Titanium Alloy Micro Groove

微铣削是实现航空微小零件精密加工的主要方法,但是受尺寸效应影响,使用该工艺加工钛合金等塑性高且强度大的材料时,易产生严重的切削变形以及毛刺等缺陷,影响微小零件加工质量。针对钛合金微槽加工过程中出现塑性变形大以及毛刺损伤严重的问题,提出超声螺线辅助铣磨加工方法,将平面加工轨迹转变为三维螺线,进而实现微铣磨工具的端面和圆柱面与工件周期性分离,降低微铣磨力,改善微槽加工质量。开展超声辅助钛合金微槽铣磨加工仿真与试验研究,对比分析不同超声振动方式对微槽毛刺尺寸、表面质量、分形维数以及微铣磨力的影响,结果表明,相比无超声辅助、纵扭超声辅助以及切向超声辅助加工方法,超声螺线辅助加工得到毛刺尺寸最小,表面粗糙度最低,分形维数最大,微铣磨力最小。钛合金微槽加工质量得到了提高。验证了超声螺线辅助加工方法在钛合金微槽加工中的优势。

Micro-milling is the main method to realize precise machining of aviation micro parts.However,affected by the size effect,when using this method to process titanium alloy and other high plasticity and high strength materials,it is easy to produce serious cutting deformation,burrs and other defects,affecting the machining quality of micro parts.To solve the problems of large plastic deformation and severe burr damage in the machining process of titanium alloy micro-groove,an ultrasonic spiral assisted milling and grinding method is proposed.The plane machining path is transformed into three-dimensional spiral,so that the end surface and cylinder surface of the micro-milling and grinding tool are periodically separated from the workpiece,which can reduce the micro-milling and grinding force and improve the micro-groove machining quality.The simulation and experiment of ultrasonic assisted titanium alloy micro-groove machining are carried out.The effects of different ultrasonic vibration modes on the burr size,surface quality,fractal dimension and micro-milling&grinding force of micro-groove are compared.The results showed that,compared with non-ultrasonic assisted,longitudinal torsion ultrasonic assisted and tangential ultrasonic assisted machining methods,ultrasonic spiral assisted machining obtained the smallest burr size,the lowest surface roughness,the largest fractal dimension and the smallest force.The machining quality of titanium alloy microgroove is improved.The experimental result verifies the advantage of ultrasonic spiral assisted machining method in titanium alloy micro-groove machining.