A new approach for predicting wear overlap geometry in ball end finish milling

Abstract

The inclination angles of sculptured surface and tilting angles of 5-axis machining change cutting time distributions (CTD) on cutting contact (CC) points. The models of element wear (EW) function of the CTD on each CC points are overlapped to form wear overlap (WO) geometry. However, the WO geometry has not been taken into account in most current tool wear models. This paper proposes a new approach for modeling of the WO geometry associated with the overlapping zones in the 5-axis machining of sculptured surfaces. The EWs in response to CTD at each CC points are modeled using probability density function. The EW is changed to the linear function of time by deforming the tool wear unit. Afterward, for each overlapping point, the WO value is calculated by using the method of the linear addition of linearized EWs. Then, the WO geometry is obtained by the inverse deformation of the unit. The proposed approach is demonstrated and validated through a case study. The predictions of WO geometry present good accordance with experimental observations in constant tilting angle and flat convex surface finish milling process.