Abstract: 【Objective】 Single-layer brazed diamond boasts high abrasive exposure and sharpness, and thus has been widely applied in the drilling of ceramic materials. However, such tools are only coated with a single layer of diamond on the surface, which limits their service life. For this reason, multi-layer brazed diamond drill bits have been developed for ceramic drilling operations. Nevertheless, multi-layer brazed diamond drill bits suffer from problems such as difficult abrasive protrusion and poor self-sharpening performance. To enhance the selfsharpening performance of multilayer nickel-based brazed diamond drill bits, this study incorporated three different pore-forming agents—ammonium bicarbonate, graphite particles, and silicon carbide particles—into the nickelbased alloy brazing material and analyzed their effects on the self-sharpening performance of the drill bits.【Method】 Different samples were prepared by varying the concentrations of three types of pore-forming agents, and the surface and cross-sectional morphologies of the samples were analyzed. By observing the pore distribution, pore size and cross-sectional microstructure inside the samples, the influence law of different pore-forming agent concentrations on the pore characteristics and micromorphology of nickel-based brazing filler metals was investigated. The optimal concentrations of the pore-forming agents were screened out through friction and wear tests and three-point bending strength tests on the samples, after which corresponding drills were fabricated for ceramic drilling experiments. Based on the comparison of the average single-hole drilling time of the drills obtained from the drilling experiments, the influence of different pore-forming agents on the self-sharpening property of the drills was analyzed.【Result】 This study systematically investigates the influence of additive concentrations on the wear resistance and flexural strength of ceramic samples, focusing on three commonly used pore-forming agents: ammonium bicarbonate, graphite, and silicon carbide. The results demonstrate that with the increase in the concentration of any one of the three pore-forming agents, both the wear resistance and flexural strength of the samples exhibit a decreasing trend. Experiments have determined that the optimal additive concentrations of ammonium bicarbonate, graphite, and silicon carbide are 10%, 5%, and 5%, respectively. At this ratio, the wear resistance and flexural strength of the samples achieve a relatively balanced state, which not only avoids the problem of poor self-sharpening performance caused by insufficient porosity at low concentrations but also circumvents the risk of sharp performance degradation due to structural looseness at high concentrations. Further ceramic drilling tests confirm that the drill bits prepared with 10% ammonium bicarbonate addition have the shortest average single-hole drilling time, exhibiting excellent self-sharpening performance.【Conclusion】 By analyzing the effects of three types of pore-forming agents on the self-sharpening property of diamond and combining the performance tests of three categories of drill bits, it is found that adding 10% ammonium bicarbonate to the nickel-based brazing filler metal is more conducive to the self-sharpening property of the multilayer brazed diamond drill bits.