Tribological Studies on Zirconium Alloy—Zircaloy-4

The low neutron absorption cross-section and good mechanical properties make Zirconium alloys suitable for the core components of nuclear reactors. Some self-mated contacts of zircaloy-4 (Zr-4) in nuclear reactors face flow-induced vibrations with few microns of amplitude. The current study aims to record the tribological behavior of self-mated Zr-4. Low amplitude reciprocating sliding friction and wear tests were conducted on Zr-4 under self-mated conditions to simulate the tribological conditions. The amplitude and sliding frequency were varied in the range of 100–300 µm and 4–7 Hz, respectively. Tests were also conducted between Zr-4 and SS-410 to confirm the material transfer phenomenon. The worn surfaces were analyzed using Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive Spectroscopy (EDS) to explore the possible wear mechanisms involved. Wear damage increases with increasing frequency and sliding amplitude. The sliding amplitude has a greater effect on wear. The microscopic exploration indicates the formation of the tribo-oxide layer, which is attributed to adhesive wear.