Environmental Protected Electropolishing Of Cu And Al Surface

Electropolishing is a very good and effective surface treating method especially for complex shape workpiece, which has good polishing effectiveness and high efficiency, and has widespread applicated in industry. But existing electropolishing solution exist the question of bad polishing effectiveness, high cost, environmental pollution and so on. For this reality, this article use the method of electrochemical polarization, research the existing electropolishing solution and technology by orthogonal test. And successful research a electropolishing solution and technology batch formula of good polishing effectiveness, high efficiency, no environmental pollution, low cost. Analysing the test sample surface topography and constituents composition after electropolishing by SEM,EDS and so on method. Making use of microhardness instrument and potentiostat and so on equipment, and analysis the variation of microhardness and corrosion resistance of test sample before and after electropolishing. At the same time, research the influence of electropolishing solution and technological parameter of Al and Cu for electropolishing effectiveness.The best batch formula of Al we get by orthogonal test is as follows:NaOH is 16g/L, Na2CO3 is 100g/L, Na3PO4 is 65g/L, ammonium oxalate is 4g/L, sodium tartrate is 2g/L, EDTA-2Na is 6g/L, the technological parameter of electropolishing is as follow:current density is 44A/dm2,polishing temperature is 80℃, polishing time is 30min, rabbling speed is 250 r/min. The surface roughness of Al test sample after electropolishing by this batch formula and technological parameter can reach 0.05μm, and surface glossiness can reach 88.5%, surface microhardness after electropolishing get to 36.5HV from 64.5HV which before elictropolishing, The corrosion resistance is enhance after electropolishing, corrosion potential rising to-0.7V from-0.8V; The best batch formula of Al we get is as follows:phosphoric acid is 850ml/L, ethanol is 90ml/L, benzotriazole is 6g/L, lactic acid is 60ml/L, ammonium acetate is 3g/L, the technological parameter of electropolishing is as follow:current density is 22A/dm2,polishing temperature is 40℃, polishing time is 20min, rabbling speed is 250 r/min. The surface roughness of Cu test sample after electropolishing by this batch formula and technological parameter can reach 0.04μm, and surface glossiness can reach 85.1%, surface microhardness after electropolishing get to 109.7HV from 167.5HV which before elictropolishing, The corrosion resistance is enhance after electropolishing, corrosion potential rising to-0.05V from 0.05V.