A real-time dressing method for metal lapping pads based on the thermal deformation effect

Surface shape and accuracy of the metal lapping pad have a significant impact on the performance of the lapping process for flat optical components, which are usually improved by the dressing process. A real-time dressing system for metal lapping pad surface shape (RDLS system) based on the bimetal thermal deformation effect is proposed. Unlike traditional dressing methods (e.g., turning dressing with a diamond tool), the real-time dressing based on the RDLS system is a material-loss-free and in-process dressing method. A full-aperture lapping turntable based on the RDLS system was designed, in which the working heat was analyzed. The displacement models of the lapping pad surface were established by regression analysis. Finally, several experiments were conducted to verify the functionality of the RDLS system. During turning dressing (turntable rotational speed n = 100 rpm), the displacement error was compensated by the RDLS system, which was caused by the working heat of the turntable shaft system. During the lapping processing for optical elements (n ≤ 20 rpm), the correction displacement was controlled by the RDLS system, which realized the real-time dressing of the lapping pad surface. The process performance of the plane optical component was optimized with the RDLS system (process parameter: the coolant temperature t). The effectiveness and practicality of the RDLS system were demonstrated experimentally.