Fabrication of Fe‒Al Coatings with Micro/Nanostructures for Antifouling Applications

Zhaorong He,Yingjun Chen,Caisong Mo,Shidong Li,Dacheng Wang,Zhiqing Fan

doi:10.3390/coatings10090902

Zhaorong He, Yingjun Chen + Show 4 more

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https://doi.org/10.3390/coatings10090902

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Journal: Coatings	Publication Date: Sep 20, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: Guangdong University of Petrochemical Technology

Abstract

Fouling is one of the common problems in heat-transfer applications, resulting in higher fouling resistance, and lower heat-transfer coefficient. This paper introduces the design and fabrication of an Fe–Al coating with micro/nanostructures on low-carbon steel by electrical discharge coating (EDC) technology to improve the antifouling property. The Fe–Al coating with micro/nanostructures is characterized by a large number of micro/nanostructures and superior anti-fouling property, which is attributed to its hydrophobic surface. The antifouling property, fouling induction period and contact angle of the Fe–Al coating with micro/nanostructures increase with the increasing gap voltage. Compared with the polished surface of low-carbon steel, the Fe–Al coating with micro/nanostructures extends the induction period from 214 to 1350 min, with a heat flux of 98 kW·m−2. After 50 adhesion tests, the contact angle of the Fe–Al coating with micro/nanostructures decreases from 6.81% to 27.52%, which indicates that the Fe–Al coating with micro/nanostructures is durable and suitable for industrial applications.

Highlights

The heat-transfer surface of a heat exchanger is in direct contact with a heat-transfer medium, which could lead to fouling deposited on the heat-transfer surface, such as inorganic crystallization fouling (ICF) [1,2], organic fouling [3], biofouling [4,5], etc
The aim of this paper is to investigate the antifouling property of the Fe–Al coating in a fouling medium, which is fabricated on a low-carbon steel surface by electrical discharge coating (EDC) technology
3b–fand show that there which are many micro–characteristics, suchFe–Al as micro–craters, micro–porous, molten balls, recast regions, are micro–characteristics, such as micro–craters, micro–porous, molten balls, and recast regions, which distributed homogeneously on the sample surface fabricated by EDC technology (EDCed coating)

Summary

Introduction

The heat-transfer surface of a heat exchanger is in direct contact with a heat-transfer medium, which could lead to fouling deposited on the heat-transfer surface, such as inorganic crystallization fouling (ICF) [1,2], organic fouling [3], biofouling [4,5], etc. Because of the inhibition effect from deposited fouling on the heat-transfer surface, higher fouling resistance (Rf ) and lower heat-transfer coefficient appeared on the heat exchanger during the operation. Researchers investigated antifouling coating, geometric topography surface, and micro/nanostructure surfaces, which modified the surface property, to mitigate the adhesion of fouling [6,7,8]. Compared with a plain surface, a hydrophobic surface with micro/nanostructures shows a better antifouling property [9,10]. Bogacz et al [11] found that the mass of crystalline deposits grew with the increased wettability of the surface. The adhesion behavior of fouling on the heat-transfer surface can be inhibited by increasing the hydrophobicity of the heat-transfer surface [12]. The anti-corrosion property of the heat-transfer surface affects the antifouling property [12,13]

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