For the highly efficient and versatile polishing of metals, isotropic etching polishing (IEP), which is based on the merging of isotropic etching holes, has been developed. In this study, the feasibility and mechanism of isotropic etching polishing of nickel-based superalloy Inconel 718 (IN718) and the polishing characteristics have been studied. The potentiodynamic experiments revealed similar trends of the cathodic, passive, second passivation, and transpassive regions in all the electrolytes, while the corrosion susceptibility of IN718 successively decreased with the increasing H₂SO₄ concentration in the electrolyte. The etching anisotropy of the IN718 precipitated with different phases can be experimentally transmuted to isotropic etching by modulating the electrolyte concentration and keeping electrolyte temperature equal or above the room temperature. Because of the positive correlation of the etching current with isotropic holes density and diameter, etching at higher currents is promoted for the rapid and proficient polishing. The surface evolution mechanism during IEP has been confirmed. The surface roughness initially increased due to the formation of etching holes, then decreased abruptly owing to the rapid merging of etching holes and finally achieved a smooth surface. The wet grounded surface of IN718 with a roughness of Sa 62.7 nm has been transformed into a mirror-like smooth surface with a roughness of Sa 0.86 nm within 300 s of IEP at optimized conditions and a high MRR of 2.73 mm³/min has been achieved.

为了对金属进行高效且通用的抛光，已经开发了基于各向同性蚀刻孔合并的各向同性蚀刻抛光（IEP）。在这项研究中，研究了镍基高温合金Inconel 718（IN718）的各向同性蚀刻抛光的可行性，机理以及抛光特性。电位动力学实验表明，所有电解质中的阴极，被动，二次钝化和超被动区域都有相似的趋势，而IN718的腐蚀敏感性随H ₂ SO ₄的增加而依次降低。电解液中的浓度。可以通过调节电解质浓度并保持电解质温度等于或高于室温，将不同相析出的IN718的蚀刻各向异性通过实验转变为各向同性蚀刻。由于蚀刻电流与各向同性的孔密度和直径呈正相关，因此促进了在较高电流下的蚀刻，从而可以快速而有效地进行抛光。IEP期间的表面演化机制已得到确认。表面粗糙度最初由于蚀刻孔的形成而增加，然后由于蚀刻孔的快速合并而突然降低，并最终获得光滑的表面。粗糙度Sa为62.7 nm的IN718湿接地表面已转变为粗糙度为Sa 0的镜面状光滑表面。已达到³ / min。