• PDF / 473,472 Bytes
• 8 Pages / 584.957 x 782.986 pts Page_size
• 21 Downloads / 214 Views

DOWNLOAD

REPORT

---

Wear and corrosion properties of AM70 magnesium alloy subjected to equal channel angular pressing (ECAP) were investigated using pin-on-disc dry sliding wear test and electrochemical impedance spectroscopy (EIS), respectively. Wear test was conducted with 30 and 40 N loads with sliding distance of 5000 m and at a constant speed of 3 m/s. Reduced coefficient of friction (COF) and wear mass loss of ECAP processed samples showed increased wear resistance. Worn surface analysis by scanning electron microscope (SEM) showed the presence of delamination, wear debris, and plowing. Energy dispersive X-ray spectrometer (EDS) revealed the occurrence of oxidation, and the wear mechanism was identified as abrasion and oxidation wear. EIS plots showed the improvement in corrosion resistance of ECAP processed magnesium alloy compared to initial condition due to grain refinement and homogeneous distribution of secondary particles.

I. INTRODUCTION

Magnesium and magnesium alloys are well identified for their significant properties like light weight, electromagnetic shielding, good castability, damping, and high specific strength which make their widespread industrial applications and considered as a green material of resources.1–4 Nowadays cast magnesium alloys are used in structural applications due to their good surface quality, dimensional accuracy, and high productivity.5,6 But, few limitations like low wear behavior and corrosion properties restrict the usage of magnesium alloys in many industrial applications.7,8 Equal channel angular pressing (ECAP) process9–11 is one of the effective tools among several severe plastic deformation (SPD) techniques in achieving ultrafine grained microstructure without much change in dimensional features.12,13 Limited literature is available on wear behavior and corrosion studies of magnesium and its alloys processed by ECAP process. Hu et al.14 conducted wear studies on extrusion shear (ES) processed AZ31B magnesium alloy by dry sliding test and showed that wear resistance was increased due to refined microstructure. Xu et al.15 reported that ECAP processed sample showed lower fluctuations in coefficient of friction (COF) due to increment in their mechanical properties and reduced wear mass loss. Orlov et al.16 conducted corrosion test on ECAP processed ZK60 magnesium alloy and showed improved corrosion resistance due to refined grain structure and distribution of intermetallic Zn and Zr. Minarik et al.17 investigated Contributing Editor: Jürgen Eckert a) Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2017.165

AE21 and AE42 magnesium alloys by electrochemical impedance spectroscopy (EIS) to study the corrosion resistance using 0.1 M NaCl electrolyte and found that Al-rich Al11RE3 dispersed particles strongly enhanced the corrosion resistance. Hadzima et al.18 observed that ECAP processed AZ31 magnesium alloy showed higher charge transfer resistance compared to cast material by conducting EIS and found that refined microstructure influenced the corrosion properties