Dynamic change of feedrate is almost inevitable in high speed milling along a curved path due to the drive limits of the machine tools. The surface topography caused by the change of feedrate, which has a significant influence on mechanical prosperities and performances of the machined part, cannot be predicted using the existing methods that only consider constant feedrate. To better understand the surface topography formation process in high speed milling and also to more effectively control the machining parameters, in this paper we present a surface topography model for a ball-end cutter, which takes varying feedrate into full consideration. Our model considers the affecting elements including the surface's local geometry, the cutting edge shape, the path interval, as well as the relative motion of tool-workpiece (especially the changes of the tool orientation and feedrate). 3- and 5-axis ball-end milling experiments, in computer simulation and physical cutting, are performed to validate the developed model. The simulation results exhibit good agreement with that of the actual cutting, thereby showing the potential of the developed model for controlling the surface topography and roughness in real NC ball-end milling.

由于机床的驱动限制，在高速铣削中沿曲线轨迹进给率的动态变化几乎是不可避免的。不能通过使用仅考虑恒定进给率的现有方法来预测由进给率变化引起的表面形貌，这对机械性能和加工零件的性能具有重大影响。为了更好地了解高速铣削中的表面形貌形成过程并更有效地控制加工参数，在本文中，我们提出了一种球形端铣刀的表面形貌模型，该模型充分考虑了进给率的变化。我们的模型考虑了影响因素，包括表面的局部几何形状，刀刃形状，路径间隔，以及刀具工件的相对运动（尤其是刀具方向和进给率的变化）。在计算机模拟和物理切削中进行了3轴和5轴球头立铣实验，以验证开发的模型。仿真结果与实际切削具有很好的一致性，从而显示出开发的模型在实际的数控球头立铣削中控制表面形貌和粗糙度的潜力。