针对长径比较大的不锈钢毛细管的高精度抛光需求,研究磨料流加工工艺的适用条件.磨料流加工工艺的关键参数是流体磨料的粘度,适合的粘度首先要确保磨料能顺利通过毛细管,其次是有满意的抛光效果.应用ANSYS Workbench Fluent进行流动仿真分析,辅助确定可行的粘度参数.仿真结果显示:常用的粘度为104,105,106 mm2/s的流体磨料,无法通过毛细管;粘度低于104 mm2/s的磨料能顺利通过,但压力过大,远超过设备的安全承载极限;粘度为5.585 Pa·s的磨料既能顺利通过毛细管,又有较均匀的流速,入口压力也在设备的安全承载范围内.据此结果,研制了低粘度的流体磨料和专用夹具,并进行抛光实验.实验表明,在毛细管内壁获得了满意的加工效果.磨料流加工工艺是解决不锈钢毛细管内壁抛光难题的有效方法.%In view of high precision polishing requirements for large length-to-diameter ratio stainless steel capillary the applicable conditions of abrasive flow machining process were investi-gated.Abrasive flow machining (AFM)technology is a relatively new finishing machining meth-od,making semi-solid extrusion through workpiece for machining surface to achieve the purpose of deburring,polishing,rounding and removing recast layer,which has been applied to the sur-face,specially shaped hole cavity,micro-hole,cross hole,bend,long tube,ceramic parts such as polishing processing.The key parameter of abrasive flow machining technology is fluid viscosity of abrasive,a suitable viscosity can ensure the smooth flow of abrasive through capillary,as well as a satisfactory polishing effect.In order to obtain feasible viscosity parameters,ANSYS Work-bench Fluent was used to analyze the flow state of abrasive.The simulation results show that the fluid abrasive with viscosity of 104 ,105 ,106 mm2/s can not flow through capillary smoothly;that with a viscosity lower than 104 mm2/s can flow through capillary smoothly,but the inlet pressure is too high,far more than the equipment safety bearing limit;5.585 Pa·s abrasive can smoothly flow through capillary at a relatively uniform velocity,and inlet pressure is within the scope of safe equipment load.According to the results,low viscosity fluid abrasive and special fixture were developed,and polishing experiments were conducted.A satisfactory processing effect on the inner wall of capillary was obtained.Abrasive flow machining technology is an effective meth-od for solving stainless steel capillary inner surface polishing problems.
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