Temperature as sensitive monitor for efficiency of work in abrasive flow machining

Work efficiency is considered as most concerned target in abrasive flow machining (AFM). It has many influence factors, such as, temperature, media viscosity, abrasive hardness, particles sharpness and density, workpiece hardness, pressure, piston moving speed, etc. The influence of temperature on work efficiency is most critical. In this investigation, both commercial AFM equipment and test rig are used to carry out AFM experiments. AISI1080, 1045 and A36 steels are used as specimens in the tests. It has been shown from AFM tests that media viscosity decreases continuously with increasing temperature. Media temperature increases with increasing cycles, which means media viscosity decreases with cycles increasing. AFM tests shows that increasing cycles extensively decrease materials removal and surface roughness decreasing efficiency. When media with different viscosity is used media with high viscosity has more effective material removal efficiency. The high viscosity media to surface roughness improvement is also better than the low viscosity media at the initial several cycle numbers. With further increasing cycles the roughness improvement difference among different media with different viscosity is reduced. It is found from Mooney viscosity–temperature relation of media that temperature rising directly results in the decrease of media viscosity. When work cycles are increased the media temperature is quickly increased. The media viscosity is also decreased dramatically. In order to understand the mechanism of decrease of material removal efficiency with temperature, computational fluid dynamics (CFD) approach is applied to predict the abrasive particles movement tendency. A two-dimensional model is constructed for AFM process. The simulation results show that the temperature rising of media results in increasing the rolling tendency of abrasive particles which causes work efficiency deteriorated.