Abstract: Based on the time step method, an improved Z-MAP algorithm is proposed to simulate the ball-end milling surface topography. In the basis of establishing of the cutter tooth movement equation, this algorithm use servo rectangular encirclement and the angle sum method to quickly obtain the instantaneous swept points on the workpiece, and introduce Newton iterative method to calculate the height of these points. It does not needed to discretize the cutting tooth, and relative to traditional Z-MAP algorithm, it not only breaks the limit which is that cutting tooth discrete segments can at most sweep across only one discrete point on the workpiece during an unit time step, but also could get higher precision and efficiency. On these bases, the influence rules of some parameters, such as path interval, feed per tooth, tool posture and the initial phase angle difference of cutter's feed, on the surface topography and roughness are analyzed. Aviation aluminum alloy 7050 is selected as milling material to make experiments, and the experimental results show that surface topographies simulated by the improved Z-MAP algorithm have higher consistency with practical processing ones, and have directive significance in rational selection of machining parameters in practical production.

Key words: ball-end milling, improved Z-MAP algorithm, simulation analysis, surface topography