Papers by Keyword: Mill-Grinding

Abstract: Based on the Kinematic analysis, the indentation fracture mechanics is used to build a force model of ultrasonic vibration mill-grinding. To verify the force model, experiments are carried out for silicon nitride ceramics with various machining parameters, meanwhile grinding forces are measured. Finally, comparison between predicted results with experimental results is presented.

Abstract: An experimental investigation is reported of the temperature measurement for ultrasonic vibration mill-grinding of silicon nitride with infrared thermovision. The effects of machining parameters such as spindle speed, feed speed, cutting depth on the surface temperature of workpiece were investigated and the reasons for the trend of temperature changes were analyzed. From the analyses, it indicates that infrared imager technology is suitable for temperature measurement in ultrasonic vibration mill-grinding of ceramics and tool wear has an important effect on the measurement results.

Abstract: In order to investigate the influences of machining parameters on surface roughness in ultrasonic vibration mill-grinding, the motion of abrasive grain is analyzed. The analysis indicates that grain and workpiece separate periodically which are beneficial for coolant entering into grinding zone to reduce grinding temperature and grinding force and improve surface quality. Experiments are carried out and detected by SEM and roughmeter, the results indicate that influences of spindle rate, feeding speed, cutting depth and amplitude decrease in turn. Through regression analysis, an empirical formula is obtained. The experiments indicate that material removal mode dominates surface roughness.

Abstract: Particle reinforced metal matrix composites (SiCp/Al composites) have proved to be extremely difficult to machine with traditional cutting processes due to serious tool-wear and high machining cost, which lead to the low machining efficiency. This paper presents the results of an experimental research on mill-grinding of SiC particle reinforced aluminum matrix composites. Based on the Taguchi experimental design method, study on the material removal rate was carried out to gain the optimal processing parameters combination by using the analysis of S/N ratio. The detailed effect of wheel speed on material removal rate through single factor experiment was also studied. Though analysis of S/N ratio and variance, the depth of cut has greatest effect on the material removal rate, followed by feed rate. And grinding wheel speed has least effect on it. But the depth of cut and feed rate affect on the material removal rate nonlinearly. In the range of machining parameters applied, the optimal processing parameters combination gained is A2B3C3, namely, v_s=11.77m/s, v_w=100mm/min, a_p=0.8mm. Material removal rate increased at first and then there was a decreasing trend with increasing wheel speed.

Abstract: This paper explains and demonstrates the machinability of dry and wet machining of SiC particle-reinforced aluminum metal matrix composites based on the experiments. The plunge surface experiments with mill-grinding method under wheel peripheral speed of up to 14.13m/s, feed rate 80mm/min and depth of cutting 50μm were carried out on a vertical CNC milling machine. The comparisons of dry and wet machining on the force composites and surface roughness (Ra) versus material removal volume were studied. The material removal volume was gained with the same machining parameters after an equal period of time. In most cases, the tangential mill-grinding force values are greater in wet machining condition than that in dry condition. But for normal mill-grinding force, the Fn values are much greater in dry machining condition than that in wet condition. And the normal mill-grinding force in wet machining increased quickly with increasing material removal volume. A better surface finish can be produced in dry machining than that produced by wet machining. The surface roughness decreased slowly with the increasing material removal volume and the surface roughness shows an insignificant decreasing trend in wet machining.

Abstract: Mill-grinding experiments were carried out on SiCp/Al to investigate effects of mill-grinding parameters and grinding wheel parameters on machined surface roughness in this paper. The machined surface topography was also analyzed. Experimental results show that surface roughness increases with increasing feed rate and the depth of the mill-grinding. The effect of mill-grinding speed on surface roughness is low. The machined surface reveals many defects. The fine grit diamond grinding wheel can reduce the surface roughness and decrease the machined surface defect. Compared to the vitrified bonded diamond and electroplated diamond grinding wheels used in the experiment, the resin-based diamond grinding wheel produces a better surface.

Abstract: In view of the present machining status of SiC particle reinforced aluminum matrix composites, the electroplated diamond wheel (80# diamond grit) was used for mill-grinding the SiC particle reinforced aluminum matrix composites and the effect of speed ratio (q) and material removal rate (MRR) on surface roughness was studied based on experiments. The experimental results show that surface roughness almost increases with the increase of speed ratio. At the same material removal rate, surface roughness increases when raising material removal rate by raising feed rate singlely or raising depth of mill-grinding singlely; surface roughness has decreasing trend with raising material removal rate by increasing feed rate and depth of mill-grinding at the same time.