Publication:
Oxidation of a refractory high entropy alloy (RHEA) at moderate temperatures for wear related applications

Placeholder

School / College / Institute

Organizational Unit

Program

KU Authors

Co-Authors

Publication Date

Language

Embargo Status

Journal Title

Journal ISSN

Volume Title

Alternative Title

Abstract

This study was initiated to exploit the poor oxidation resistance of a RHEA, namely HfNbTaTiZr, to enhance its surface hardness and wear performance. In this regard, samples sliced from vacuum arc melted HfNbTaTiZr ingots having a hardness of -400 HV were held at two different temperatures (450 and 600 degrees C) for 3 h in air. The structural examinations conducted by using X-ray diffraction (XRD) and Raman analysis along with an energy dispersive spectrometer (EDS) equipped scanning electron microscope (SEM) revealed that the samples were covered with a complex HfNbTaTiZrO11 type oxide layer (OL) having the hardness of -1550 HV. The average surface roughness (Ra) and the thickness of the OLs were measured as -0.13 mu m and - 1 mu m after oxidation at 450 degrees C and - 0.29 mu m and - 8 mu m after oxidation at 600 degrees C, respectively. The protective nature of the OLs was confirmed by dry sliding wear tests employed at room temperature against alumina balls under a contact pressure of -0.5 GPa. This led to 240- and 45-times higher wear resistance for the samples oxidized at 450 and 600 degrees C, respectively. During the wear tests, the untreated sample was exposed to severe wear owing to the accumulation of heavy plastic deformation at the contact surface, while for the oxidized samples wear progressed in an elastic deformation regime on the OLs resulting in mild wear. However, the roughness of the OLs played a crucial role on the wear resistance of the oxidized samples, so that the oxidation temperature of 600 degrees C, which imposed a higher Ra value, resulted in a reduction in wear resistance when compared to the oxidation temperature of 450 degrees C, which formed a smoother OL.

Source

Publisher

Elsevier Sci Ltd

Subject

Materials science, Metallurgical engineering

Citation

Has Part

Source

International Journal of Refractory Metals & Hard Materials

Book Series Title

Edition

DOI

10.1016/j.ijrmhm.2023.106223

item.page.datauri

Link

Rights

Copyrights Note

Endorsement

Review

Supplemented By

Referenced By

0

Views

0

Downloads

View PlumX Details