Alumina abrasive wheel wear in ultrasonic vibration-assisted creep-feed grinding of Inconel 718 nickel-based superalloy

Abstract

Blade root with a special fir-tree shape is a critical connection part in an aero-engine. This part has high requirements on the surface finish and geometrical accuracy. At present, the tangential ultrasonic vibration-assisted profile grinding (UVAPG) is an effective method for machining the blade roots. During UVAPG, the wheel wear degrades the surface finish and geometrical accuracy. However, the characteristics of the wheel wear in UVAPG are not fully revealed. This study proposes an analytical wear model by considering the intermittent grinding behavior of a grinding edge, the number of active grinding edges, and the effects of wheel profile on the tool wear. The model is experimentally demonstrated to be applicable to predicting the wear volume in UVAPG with a maximum error of 4.2 %. Based on the model, the tangential ultrasonic vibration increases the average unchanged chip thickness and the number of active grinding edges. UVAPG causes an approximately 22 % increase in wear volume at the steady wear stage compared with the conventional grinding. The wear speeds vary at different regions of a profile wheel. The convex regions represent higher wear speeds than the concave regions on the wheel.