Title: Mechanical and tribological characteristics of sintered Fe-Ni-Cr alloy subjected to high-frequency ultrasonic peening
Authors: Jong-Deok Kim; In-Sik Cho
Addresses: Molds & Dies Technology R&D Group, Korea Institute of Industrial Technology, 406-840, 7-47, Songdo-Dong, Yeonsu-Gu, Incheon, Republic of Korea ' Department of Hybrid Engineering, Sun Moon University, 336-708, 100, Kalsan-ri, Tangjeong-Myun, Asan-Si. Chungnam, Republic of Korea
Abstract: In this paper, Fe-Ni-Cr alloy friction test specimens were prepared by direct metal laser sintering (DMLS); some specimens were further treated by hot isostatic pressing (HIP) at 1,050°C and 1,150°C in order to reduce the porosity and increase the density of the specimens. Some of the HIP-treated specimens were subjected to high-frequency ultrasonic peening (HFUP) with the aim of improving their tribological properties. Wear tests were performed on a tribometer with a ball-on-disk configuration under dry conditions, while nanoscratch tests were performed using the ultra nanoscratch testing (UNST) technique. The objective of this study is to investigate the effects of the FUP technique on friction reduction and wear resistance of the DMLSand HIP-treated Fe-Ni-Cr alloy specimens. The results of the friction and nanoscratch tests showed that the friction coefficient and wear resistance of the HFUP-treated specimens were lower and higher than those of the polished specimens, respectively. However, these results showed that the tribological properties of HFUP-treated specimens were dependent upon the temperature condition of the HIP process. The microstructural characterisation was conducted by optical microscope (OM) and scanning electron microscope (SEM).
Keywords: direct metal laser sintering; DMLS; hot isostatic pressing; HIP; high-frequency ultrasonic peening; HFUP; friction; wear resistance; nanoscratch tests; Fe-Ni-Cr alloys; iron; nickel; chromium; tribology; temperature; microstructure.
International Journal of Surface Science and Engineering, 2014 Vol.8 No.2/3, pp.239 - 254
Received: 04 Feb 2013
Accepted: 24 Jul 2013
Published online: 17 Apr 2014 *