Study On Optimization Of Tribological Properties And Geometric Parameters Of Cortical Bone Drilling With Microtexture Cutter

In recent years,more and more research has been done on surgical operations,and the requirements for surgical procedures have become higher and higher.In this case,the drilling quality will directly affect the rehabilitation and wound healing of patients,while the tool has a direct impact on the drilling quality,so micro-texture technology is applied to the surface of the tool from the engineering field to the medical field.It is found that the high performance surface texture can reduce wear and adhesion,effectively reduce drilling force and improve drilling quality.In this paper,surface micro-texture technology is applied to bone drilling,and the wear-reducing mechanism of micro-texture cutters is expounded.The results of tool drilling with or without micro-texture are compared and analyzed by experiments.Then,the relationship between the geometric characteristic parameters of micro-texture(micro-pit diameter,micro-pit depth and micro-pit spacing)and friction coefficient is analyzed by regression orthogonal test,and the micro-texture parameters are optimized.Specific research contents are as follows:(1)The friction reduction mechanism of micro-textured surface in friction process and the influence of cutting force in cutting process are analyzed.The friction reduction mechanism of surface texture in friction contact process and the influence of surface texture cutter on cutting force and friction coefficient are explained theoretically.(2)In the cutter-chip contact area on the rake face of medical stainless steel twist drill,micro-pit array textures with different size parameters are machined by laser marking machine.(3)The process parameters of surface micro-texture preparation were used to prepare disc samples and porcine cortical bone samples for friction and wear tests.Dry friction tests were carried out to analyze the influence of micro-texture parameters on friction coefficient in the study area.The friction properties of micro-pit texture surface and non-texture surface under dry friction were compared and analyzed,and the wear reduction mechanism of micro-pit texture was revealed.(4)Based on the results of friction test data,a prediction model of friction coefficient of surface micro-texture was established by regression orthogonal test method.(5)To study the wear characteristics of the optimum micro-texture twist drill,the accuracy of the prediction model was analyzed through the cortical bone drilling test,and the genetic algorithm was used to optimize the prediction model.Within the scope of the research parameters,the optimum combination of the micro-pit texture geometric parameters with the minimum friction coefficient was obtained.