Application of AFM-Based Techniques in Studies of Corrosion and Corrosion Inhibition of Metallic Alloys

Kiryl Yasakau

doi:10.3390/cmd1030017

Abstract

In this review several scanning probe microscopy techniques are briefly discussed as valuable assets for corrosionists to study corrosion susceptibility and inhibition of metals and alloys at sub-micrometer resolution. At the beginning, the review provides the reader with background of atomic force microscopy (AFM) and related techniques such as scanning Kelvin probe force microscopy (SKPFM) and electrochemical AFM (EC-AFM). Afterwards, the review presents the current state of corrosion research and specific applications of the techniques in studying important metallic materials for the aircraft and automotive industries. Different corrosion mechanisms of metallic materials are addressed emphasizing the role of intermetallic inclusions, grain boundaries, and impurities as focal points for corrosion initiation and development. The presented information demonstrates the importance of localized studies using AFM-based techniques in understanding corrosion mechanisms of metallic materials and developing efficient means of corrosion prevention.

Highlights

Corrosion of metallic materials and structures is a heavy burden for the economy which costs about 3.4% of the global GDP (2013) according to the Application and Economics of Corrosion Technology (IMPACT) study released by NACE International [1]
The first part of this review briefly addresses the principles of atomic force microscopy (AFM), and AFM-based techniques such as scanning Kelvin probe force microscopy (SKPFM) and electrochemical AFM (EC-AFM)
This review has provided information on the main principles of AFM, SKPFM, and EC-AFM

Summary

Introduction

Corrosion of metallic materials and structures is a heavy burden for the economy which costs about 3.4% of the global GDP (2013) according to the Application and Economics of Corrosion Technology (IMPACT) study released by NACE International [1]. A typical aerospace aluminum alloy such as AA2024 contains copper as the main alloying element It has a much higher corrosion rate than pure aluminum due to the adverse effects of copper-containing intermetallics which induce high susceptibility to localized corrosion [10,11,12,13]. Electron microscopy investigations help to elucidate localized corrosion events associated with intermetallics in the depth of the metallic matrix [14,15] General electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and DC-polarization are commonly employed to reveal interfacial characteristics and corrosion kinetics of different metallic phases and alloys [19,20,21]. This review aims to provide an overview of the state of the art in applications of atomic force microscopy-based techniques for corrosion investigation of different metals and alloys.

Principles of Main AFM Based Techniques

In Situ AFM Investigation of Metallic Surfaces

Findings

Conclusions