An accurate 3D surface topography model for single-point diamond turning. (November 2018) - He, C.L.
Abstract: In this work, an accurate surface topography model that considers the effects of kinematics, dynamics and material defects of a workpiece is theoretically formulated. For kinematic-dependent factors, tool edge waviness, material spring back, and plastic side flow are successively integrated, and a quadratic distribution function is proposed to determine the overall effects of material spring back and plastic side flow. For dynamic factors, a multifrequency vibration model is first proposed and analysed. The complication of the surface topography and irregularities of the surface bulge segments are attributed to the interaction effect of multifrequency events according to the simulation and measurement results corresponding to vibration. For the material defects of a workpiece, coupled with measurement results, a newly developed method utilized as an additional function method is elaborated to simulate the influences of these results on the surface topography. The protuberance of hard inclusions in the material matrix is due to their Young's modulus, which is much larger than that of the material matrix. Thus, a theoretical formula considering the elastic deformation is established to calculate the effects of grain boundaries and the protrusions of hard inclusions. Theoretical analyses and experimental observations prove that under identical cutting conditions, the diversity of the surface finish is derived from the distribution and size of material defects. The presence of numerous defects in the material matrix will facilitate enlargement of the irregular component of the surface topography. Highlights: An analytical surface topography model for diamond turning is developed. Effect of multifrequency vibration on surface profile is modeled. Additional function method is proposed to model the impacts of material defects.