|| In this study, a conductive polymer is used as tool electrode in machining the |
stainless steel surface by electrochemical buffing. Using a very small working current of
this conductive polymer, the material of the workpiece is dissolved, and the peaks on
the workpiece surface is buffed by the abrasive simultaneously. A mirror-like surface
can be achieved with high efficiency using this novel method.
In the micro-electrochemical machining experiments, the initial surface roughness
of the workpiece is about Rmax = 1.645 μm, the average speed of electrode 25
mm/sec, the machining time 10 min, the electrolyte temperature 25℃, and the stroke 10 mm. The variable conditions are given as follows: the sodium nitrate
(NaNO3) electrolyte of 0 to 40 wt%, the normal load of 0 to 20 N, and the working
current of 0 to 100 mA. Experimental results show that the minimum surface roughness
of the workpiece can be achieved to about Rmax = 0.3μm at the electrolyte concentration
of 20 wt%, the working current of 25 mA, and the normal load of 10N, which is
selected as the optimum operative parameters in the following.
The silicon carbide with average particle size of 9.5μm is added to conduct the
electrochemical buffing experiments. Compared with the micro-electrochemical
machining method, results show that the maximum machining depth increases to about
two times, and the surface roughness decreases to about 50%. In this condition, the
mirror-like surface of the workpiece with the working depth of 1.5μm and Rmax of
0.15μm can be achieved.