Investigation of the Structural Heterogeneity and Corrosion Performance of the Annealed Fe-Based Metallic Glasses

Dandan Liang,Jo-Chi Tseng,Yuanfei Cai,Jun Shen,Xiaodi Liu,Gang Xu

doi:10.3390/ma14040929

Abstract

This study investigated the structural heterogeneity, mechanical property, electrochemical behavior, and passive film characteristics of Fe–Cr–Mo–W–C–B–Y metallic glasses (MGs), which were modified through annealing at different temperatures. Results showed that annealing MGs below the glass transition temperature enhanced corrosion resistance in HCl solution owing to a highly protective passive film formed, originating from the decreased free volume and the shrinkage of the first coordination shell, which was found by pair distribution function analysis. In contrast, the enlarged first coordination shell and nanoscale crystal-like clusters were identified for MGs annealed in the supercooled liquid region, which led to a destabilized passive film and thereby deteriorated corrosion resistance. This finding reveals the crucial role of structural heterogeneity in tuning the corrosion performance of MGs.

Highlights

Due to the homogenous amorphous structure, metallic glasses (MGs) exhibit superior strength and hardness, excellent corrosion resistance, low cost, etc. [1,2]
Wagner and Liu et al characterized the inhomogeneous distribution of local elastic modulus and energy dissipation utilizing atomic force microscopy (AFM) [5,6], which quantified the structural heterogeneity in MGs
Annealing MG at 0.7 Tg for 30 min led to the reduced free volume and the shrinkage of the first coordination shell in the local atomic structure, which could improve the passivity and corrosion resistance, indicating from the decreased ipass, elevated Epit, and increased Rc

Summary

Introduction

Due to the homogenous amorphous structure (no grain boundaries, inclusions, or precipitates), metallic glasses (MGs) exhibit superior strength and hardness, excellent corrosion resistance, low cost, etc. [1,2]. Due to the homogenous amorphous structure (no grain boundaries, inclusions, or precipitates), metallic glasses (MGs) exhibit superior strength and hardness, excellent corrosion resistance, low cost, etc. With the continuous exploration of amorphous structure, the homogenous microstructure of MGs is found out to be heterogeneous at the nanoscale or microscale. Hirata et al proved the local atomic order in metallic glasses by nanobeam electron diffraction combined with ab initio molecular dynamics simulation [3] and revealed the relation between the nanoscale spatial heterogeneity and the local structure variation from icosahedron-like to tetragonal crystal-like order in MGs [4]. Understanding the structural heterogeneity of MGs and its relation to the intrinsic properties is an area of interest for researchers [9]. Tailleart et al [19]

Methods

Results

Conclusion