Research on electrolytic plasma polishing process for internal flow channel of superalloys alloy additive manufacturing parts

To solve the problem of poor surface quality of internal channel parts in additive manufacturing, the internal electrode electrolyte plasma polishing technology was used to improve the surface quality of the workpiece. The influence of different process parameters on the surface roughness of the internal channel was studied by orthogonal test. The experimental results show that for small caliber channels, polishing is more suitable for low voltage conditions. Under the conditions of polishing voltage 40 V, electrolyte temperature 80°C, moving speed of cathode wire 3 mm/min, and peristaltic pump speed 100 rpm, the roughness of the GH3536 inner channel sample is reduced from 15.1 to 2.793 μm. The order of influence of each factor is as follows: firstly voltage, secondly electrolyte temperature, then cathode wire traveling speed, and finally peristaltic pump speed. The roughness of GH4169 was reduced from 6.724 to 0.47 μm by polishing experiment. The results of the internal surface performance test show that the spherical powder on the surface of the workpiece disappears after polishing through the internal flow channel, the electrolyte component residue is not detected on the surface of the internal flow channel, and the corrosion resistance is significantly improved.