Fine Processing Of The Er Fluid-assisted Mechanism

Particle-dispersed Electrorheological-fluid (ER fluid) is a type of foundational fluid material. The fluid is made from uniform suspensions of an insulating base fluid with lower dielectric constants and particles with high dielectric constants. It has an especial characteristic that its viscosity can be dramatically controlled by external electric field. Following the applied electric field, the ER particles become polarized, such as semiconductor material, rapidly aggregate into fibrous columns. When the external electric field reaches a certain voltage ER fluid will be transited from a fluid state to a solid-like state. So it is convenient to realize energy transformation efficiently by utilizing such electric-controlled characteristic of ER fluid.In our research, particle-dispersed ER fluid is used as a special instantaneous bond to cohere abrasive particles in the ER fluid so as to form dynamical tiny grinding wheel in grinding for fine machining. Thus, when abrasive particles is put into the ER fluid and electric power is supplied such that the needle-like tool is cathode and the workpiece is anode, one end of the electric force lines will converge on the tip of the tool and the other end of the electric force lines will be an emissive shape. The abrasive particles are banded in the ER particles and this time a tiny wheel is formed. By regulating some parameters such as voltage, ingredient, volume rate of ER fluid, machining time, as well as distance between cone-tool and workpiece etc, the size, rigidity, and abrasive mutual combine-intensity of the micro grinding wheel can be controlled in order to achieve an expected machining effect.Experiments have been carried out by using optical-microscope and SEM to analyze the characteristics of processed workpiece surface and discover three material removal modes: fragile mode, plastic removal mode and both coexistence mode. Based on the experiments, relationship between material removal modes and the size, intensity of dynamic tiny grinding wheel is presented in this paper to obtain ideal material removal mode for the sake of achieving perfect machining surface by controlling correlative electrics parameters and physics parameters.