Highly efficient smoothing of Inconel 718 via electrochemical-based isotropic etching polishing

Muhammad Ajmal，Khan1; Yi，Rong1; Zhan，Zejin1; Ji，Jianwei1; Zhang，Xinquan2; Deng，Hui1

2021-09-01

10.1016/j.precisioneng.2021.03.005

PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY   影响因子和分区

0141-6359

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 HSO 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 mm/min has been achieved.

Electrochemical etching Etching anisotropy Inconel 718 Polishing Roughness

SCI ; EI

英语

第一 ; 通讯

WOS:000651834800002

20211410160719

Corrosion ; Electrolytes ; Etching ; Merging ; Nickel alloys ; Sulfuric acid ; Surface roughness

Nickel Alloys:548.2 ; Machining Operations:604.2 ; Electric Batteries and Fuel Cells:702 ; Chemical Reactions:802.2 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Inorganic Compounds:804.2 ; Physical Properties of Gases, Liquids and Solids:931.2

ENGINEERING

2-s2.0-85103337493

Scopus

1.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,No. 1088, Xueyuan Road,518055,China
2.School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai,200240,China

Muhammad Ajmal，Khan,Yi，Rong,Zhan，Zejin,et al. Highly efficient smoothing of Inconel 718 via electrochemical-based isotropic etching polishing[J]. PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY,2021,71:119-129.

Muhammad Ajmal，Khan,Yi，Rong,Zhan，Zejin,Ji，Jianwei,Zhang，Xinquan,&Deng，Hui.(2021).Highly efficient smoothing of Inconel 718 via electrochemical-based isotropic etching polishing.PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY,71,119-129.

Muhammad Ajmal，Khan,et al."Highly efficient smoothing of Inconel 718 via electrochemical-based isotropic etching polishing".PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY 71(2021):119-129.