Papers by Author: Jin Fu Ding

Abstract: In order to grasp the microcosmic mechanism of abrasive flow machining (AFM), find out the real law of grain cutting workpiece surface, make out a reasonable process parameters and improve the abrasive flow processing efficiency. The process of grain (near to workpiece surface, called as active grains) cutting workpieces material has been analyzed and the cutting force model has been established in present work. Firstly, at the beginning of the present work, the general process of grain cutting, wearing or deburring workpiece surface has been researched. Theoretical analysis shows that the cutting force not only derives from static force, such as abrasive medium viscoelasticity and grain squeezing, but also dynamic force, such as grain impacting load on the workpiece surface. In ordering to prove the dynamic force exists, one or two main dynamic process parameters (such as abrasive viscosity, extrusion pressure, piston velocity) are chosen, dynamic force is most sensitive to the variation of which, meantime, static force is not, and then the effects of main dynamic process parameters on cutting force value have been compared with the effects of others process parameters by several experiments in the present work. The experimental results show that with the same proportion of variation of process parameters, the change in cutting force (mainly axial cutting force) consists with theoretical results very well in some degree.

Abstract: In order to reduce the cost, improve the surface of workpiece machined by AFM and make out reasonable technological parameters of AFM, AFM theory model has been developed in the present work. The process parameters such as pressure, piston velocity, temperature and viscosity impacting on the workpiece surface quality have been researched. Firstly, the properties parameters of abrasive media such as viscous have been figured out with formulas based on the characters of abrasive media. And then the force between abrasive near to the workpiece surface and workpiece has been modeled with fluidics equations and dynamics equations. However, different parameter value leads to different force and different force has different surface quality (Ra) of workpiece. The calculation result is similar to the experiment result to some extent. Obviously, this model is helpful to establish the reasonable process parameters.

Abstract: In order to study the finishing mechanism of abrasive flow machining (AFM), the model of material removal and solving method of surface roughness during material deformation have developed based on axial force and radial force. However, the axial force and radial force have been respectively measured by two pressure transducers fixed in the fixture. Both the material removal weight and surface roughness of workpiece have been calculated and measured during AFM experiments. The conclusions arrived by the analysis about the results of theoretical calculation are in agreement with the experimental AFM in some extent.

Abstract: The surface roughness of the hydraulic prop had an important effect on the wear resistance, fatigue strength and property of fit. The ultrasonic surface rolling extrusion (USRE) processing experiment was employed to improve the surface roughness of the hydraulic prop, some machine parameters such as the tools transfer magnitude, feed were studied in detail, the contact style roughness tester( Mahr S2) was used to test the surface roughness of the workpiece. The experiment results showed that the USRE could improve the surface roughness evidently, the Ra value from 0.976μm reduce to 0.105 μm by one-hit machining. The feed was linear with the surface roughness, and when the tools’ amplitude was 6.5~8.5, there were a better surface roughness Ra 0.090μm. USRE processing the surface time and again could improve the surface state.

Abstract: The machining method and characteristic of the ultrasonic extrusion-rolling machining was introduced in the paper. According to the machining characteristic, the kinematic analysis of the machining mechanism and surface anamorphic was analyzed too. And then the correlative theory of tribology was adopted to discuss the relation between surface anamorphic quantity and the technological parameter. The theory foundation was afforded for the choice of technological parameter.

Abstract: In order to solve the difficulty of polishing process at present. Polishing posture was analyzed at the contact spot of polishing cutter with work piece in this paper, and how to layout the polishing path and its built method were discussed emphatically, carried out simulation analysis with Mastercam software, and proposed suitable building method of path according to different region using different polishing method. Finally, it is proved that an ideal effect would be achieved.

Abstract: In order to improve the surface quality and machining efficiency for mold polishing. Digital automatic Polishing is a good method, MasterCAM is the software that often is used for CAM machining, path layout and building method are emphasized according to the MasterCam’s curved surface processing path setting method, and aimed at the different curved surface use different polishing path building method, at last, the rationality of the polishing path building was validated.