Comparative Analysis on the Structure and Properties of Iron-Based Amorphous Coating Sprayed with the Thermal Spraying Techniques

Amjad Iqbal,Muhammad Yasir,Moazam Maqsood,Muhammad Atiq Ur Rehman,Sumera Siddique

doi:10.3390/coatings10101006

Abstract

Iron-based amorphous coatings are getting attention owing to their attractive mechanical, chemical, and thermal properties. In this study, the comparative analysis between high-velocity oxy-fuel (HVOF) and atmospheric plasma (APS) spraying processes has been done. The detailed structural analysis of deposited coatings were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Mechanical and electrochemical properties were investigated by using micro-Vickers hardness testing, pin-on-disc tribometry and potentiodynamic analysis. The microstructure comparison revealed that HVOF-coated samples had better density than that of APS. The porosity in APS-coated samples was 2 times higher than that of HVOF-coated samples. The comparison of tribological properties showed that HVOF-coated samples had 3.9% better hardness than that of coatings obtained via APS. The wear test showed that HVOF-coated samples had better wear resistance in comparison to APS coatings. Furthermore, the potentiodynamic polarization and electrochemical impedance spectroscopy showed that the HVOF-coated samples had better corrosion resistance in comparison to APS-coated samples.

Highlights

Bulk metallic glasses (BMGs) are considered widely as one of the best coating materials due to their ultra-high strength, high hardness, large elastic strain limits, hydrophobicity, magnetic properties, good corrosion and wear resistance, thermal stability, relatively low cost, and good glass formability (GFA) [1,2,3]
The dense amorphous structure was obtained for high-velocity oxy-fuel (HVOF)
The comparative analysis of the tribological properties of shows that the HVOF-coated samples have better hardness tribological properties of HVOF and atmospheric plasma spray (APS) shows that the HVOF-coated samples have better hardness and higher wear resistance

Summary

Introduction

Bulk metallic glasses (BMGs) are considered widely as one of the best coating materials due to their ultra-high strength, high hardness, large elastic strain limits, hydrophobicity, magnetic properties, good corrosion and wear resistance, thermal stability, relatively low cost, and good glass formability (GFA) [1,2,3]. In order to cope with this problem, BMG-based composite coatings and iron-based amorphous coatings are fabricated by thermal spraying techniques, which is an attractive approach [4]. The thermal spraying processes, high-velocity oxy-fuel (HVOF) and atmospheric plasma spray (APS) have been widely used to fabricate amorphous coatings due to their low cost, flexibility regarding substrate material, relatively fast cooling rate, and high deposition rate [5,6].

Methods

Results

Conclusion