The influence of the feed amount on the surface roughness of the micro-axis when the back-feeding amount ap=0.04 mm and the spindle rotation speed n=2000 r/min. Under this set of cutting conditions, the fine shaft can only be formed by turning in the feed amount f in the range of 0.2 to 1.5 mm/min. In the formable range, the feed amount is proportional to the surface roughness value and has a significant effect. The influence of the change of the back-feeding amount on the surface roughness of the micro-axis is given when the feed rate f=0.mm/min and the spindle speed n=2000r/min. When ap<0.02mm, the tool touches the micro-axis and then bends it due to factors such as insufficient rigidity. In the range of back-feeding ap=0.02-0.08mm, the surface roughness value does not change much, which indicates that the influence of different back-feeding knives on surface roughness is small. When ap=0.04mm, f=0.2mm/min, the influence of the spindle speed on the surface roughness of the fine shaft is changed. It can be seen from the figure that when n<2000r/min, the surface roughness value increases as the spindle speed decreases. This is related to the special variation of cutting force during the micro-cutting of diamond tools. Under this set of cutting conditions, the spindle rotation speed is changed, and the feed amount per revolution also changes. At low speed, when the feed amount is small to a certain extent, the extrusion of the diamond cutter edge on the workpiece is intensified. Compared with the contact area between the turning tool and the chip, the contact area between the turning tool and the workpiece is gradually increased. At this time, the ratio of the force acting on the cutting edge and the flank face in the total cutting force increases. The radial force Fr is greater than the tangential force Fz, and the change in Fr directly affects the surface roughness value and the processing of the micro-axis. This also explains why the tool touches the micro-axis when n<1000r/min. When n>4000r/min, the fine shaft is curved, and as the spindle speed increases, the bending deformation is intensified due to the centrifugal force. Fig. 2 Effect of feed rate on surface roughness of micro-axis Fig. 3 Effect of the amount of back-feeding knife on the surface roughness of micro-axis Figure 4 Effect of spindle speed on surface roughness Test results and some parts A scanning electron microscope (SEM) photograph of a 7 μm micro-axis at the end was semi-finished to Ø100 μm and then turned by a synthetic single crystal diamond tool. The processing parameters are: n=2000r/min, f=0.2mm/min, ap=0.1mm; with the same parameters, the actual cutting time for finishing is about 20s for a shaft with a diameter of 11μm and a length of 65μm. Previous Next Moving Head Beam Light,Dj Lighting Moving Head,Dmx Moving Head Light,Disco Moving Head Light EV LIGHT Guangzhou Co., Ltd , https://www.evstagelights.com
Research on turning technology of large aspect ratio micro-axis (3)