DD6镍基单晶高温合金电化学抛光实验

马宁; 李兴琦; 李青

doi:10.3969/j.issn.2095-1248.2025.02.001

沈阳航空航天大学学报 ›› 2025, Vol. 42 ›› Issue (02) : 1 -8. DOI: 10.3969/j.issn.2095-1248.2025.02.001

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DD6镍基单晶高温合金电化学抛光实验

马宁 ^1a^,^1b ,
李兴琦 ^1a^,^1b ,
李青 ²

作者信息 +

Experiment on electrochemical polishing of DD6 nickel-based single crystal superalloy

Ning MA ^1a^,^1b ,
Xingqi LI ^1a^,^1b ,
Qing LI ²

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摘要

为了进一步提高DD6镍基单晶高温合金表面质量和耐蚀性能，选取甲酰胺-氨基磺酸溶液，对DD6镍基单晶高温合金开展电化学抛光实验，研究了抛光电压、电解液浓度和抛光时间对抛光后表面质量的影响。结果表明，在抛光电压为20 V、电解液浓度为1.2 mol/L、抛光时间为2 min条件下，表面粗糙度最低值为0.358 $μ m$ ，此时表面效果达到最佳。同时发现，在高电压（30 V）和高酸浓度（1.6 mol/L）的条件下，DD6样件表面出现不规则的蚀坑和杂质颗粒，表面质量较差。经过电化学抛光，DD6样件的光亮度明显提高，通过实验得出抛光电压是影响表面光亮度的关键参数。分析表面元素得出，抛光后表面O元素含量少，说明抛光过程中并未生成含有金属氧化物的钝化膜。DD6样件抛光前后Tafel曲线表明，抛光后DD6样件的自腐蚀电位更正，自腐蚀电流更小，因此电化学抛光也提升了DD6样件的耐蚀性能。

Abstract

In order to improve the surface quality and corrosion resistance of DD6 nickel-based single crystal superalloy，the electrochemical polishing experiment of DD6 nickel-based single crystal superalloy was carried out by formamidesulfamic acid solution，and the effects of polishing voltage，electrolyte concentration and polishing time on the surface quality after polishing were studied. The results show that under the conditions of 20 V，electrolyte concentration 1.2 mol/L and of 2 min，the surface roughness is the lowest value of 0.358 $μ$ m，and the surface effect reaches the best at this time. Under the conditions of high voltage （30 V） and high acid concentration （1.6 mol/L），irregular pits and impurity particles appeare on the surface of DD6 samples，and the surface quality is poor. After electrochemical polishing，the brightness of DD6 samples is improved，and the polishing voltage is the key parameter affecting the surface brightness.It is analyzed that the surface O element content is low after polishing，indicating that no passivation film containing metal oxides is formed during the polishing process.The Tafel curves before and after polishing of DD6 samples show that the corrosion potential of DD6 samples is larger and the corrosion current is smaller after polishing，so the corrosion resistance of DD6 samples is improved by electrochemical polishing.