利用交变旋转磁场去除叶片气膜孔毛刺的试验研究

对航空发动机叶片采用电火花打出气膜冷却孔后产生的毛刺,用传统的加工方法难以去除,利用交变旋转电磁场带动微细磁针旋转与气膜冷却孔发生碰撞可有效去除叶片气膜冷却孔的毛刺。从理论上分析了磁力研磨法的工作原理、磁力研磨过程中磁针的运动方式以及影响磁力研磨加工效率的因素,并对气膜冷却孔进行磁力研磨抛光试验;采用3D超景深显微镜观察叶片气膜冷却孔研磨前后表面微观形貌的变化。试验结果表明:利用磁力研磨法可以有效去除叶片气膜冷却孔的毛刺,使表面形貌得到改善,满足工件的使用要求。

Experimental Study on Film Cooling Hole Deburring by Alternating Rotating Magnetic Field

After processed by electrical discharge machining (EDM),the film cooling hole of aircraft engine blade was surrounded by burr.It is difficult to remove the burr by using the method of traditional polishing.Using rotating electromagnetic field to drive the tiny magnetic pin rotating and collide with film cooling holes can effectively remove the burr which on the edge of film cooling holes.The principle of magnetic abrasive finishing (MAF),the motion trajectory of magnetic pin during in MAF,and the influence factor of magnetic abrasive machining efficiency ware theoretically analyzed.Then the film cooling hole of blade was accomplished in the MAF experiment.The surface topography of the film cooling hole before and after polishing by the 3D depth of field electron microscopy is observed and recorded.The result shows that using magnetic abrasive finishing could achieve a good effect on removing burr on film cooling holes,improve the surface morphology and meet the requirement and precision.