Surface Evolution and Optimizing Strategy for Polishing Natural Heterogeneous Marble Using Sol-Gel Diamond Pad

Inefficiency and poor quality are the main problems in polishing natural heterogeneous marbles using sol-gel (SG) diamond pads. A strategy was proposed to address these issues by establishing a natural heterogeneous marble polishing model based on the optimal polishing time. The surface evolution and optimal time for polishing natural heterogeneous marble were systematically investigated. Six different types of marbles were polished by the sol-gel diamond pads. The surface glossiness, roughness, peak–valley value, and surface morphology of the marbles were measured and analyzed after different polishing times. The optimal polishing time for each marble was revealed using sol-gel diamond pads. The experimental results show that the standard deviation of the hardness distribution of marble tile significantly affects the material removal inconsistency and evolution of the surface during polishing, resulting in different optimal polishing times for different kinds of marble. The larger the standard deviation of the hardness of the marble is, the more difficult it is to obtain better surface quality, and the orange peel effect is more likely to occur. Furthermore, the optimal polishing time has a good logarithmic relationship with the standard deviation of the hardness distribution. Finally, a curve model of the optimal polishing time for each marble was established. The determination of the optimal polishing time can effectively optimize the polishing process, simplify the processing flow, improve production efficiency, and reduce production costs. The proposed method and obtained results in this paper can provide a theoretical basis and reference for polishing other types of heterogeneous stone materials.