Tribological characteristics of high strength low alloy steel under various environmental conditions

High strength low alloy steel has excellent heat resistance and high strength. As it is commonly used as gun barrel material, a long service life and superior wear resistance are necessary for steel components. Here we investigated the wear characteristics of high strength low alloy steel surfaces under various environmental conditions, using a pin-on-disk wear test. Oxidation and wear debris effects on the coefficient of friction (COF) of the alloy steel were examined under air and argon (Ar) gas flow at atmospheric conditions

Effect of geometrical parameters in micro-grooved crosshatch pattern under lubricated sliding friction

Tribological test was carried out using a pin-on-disc geometry with textured SKD11 pin on bearing steel disc, under sliding in paraffin oil. Micro-grooved crosshatch pattern has been fabricated with various angles and widths. The effects of geometrical parameters on friction were mainly examined in mixed and elastohydrodynamic lubrication. The results show that friction control can be achieved by fabricating the micro-grooved crosshatch pattern on a contact surface. It is observed that each geometrical parameter of texture influence on friction, especially decrease of groove aspect ratio and increases of groove sliding length show friction reduction performance. Crucial parameter Gl was proposed for micro-grooved crosshatch texture. The friction mechanism is explained by micro fluid flow with limited theoretical approach

WTC2005-63852 SLIDING WEAR BEHAVIOR OF PLASMA SPRAYED ZIRCONIA CERAMIC COATING UNDER DIFFERENT CONDITIONS

ABSTRACT The sliding wear behavior of ZrO 2 -22wt%MgO (MZ) and ZrO 2 -8wt%Y 2 O 3 (YZ) deposited on a cast aluminum alloy with bond layer (NiCrCoAlY) by plasma spray against a SiC ball was investigated under dry and lubrication conditions at room temperature. At all load conditions, the wear mechanisms of the MZ and YZ coatings were almost the same. The wear mechanism involved material transfer and pullout under dry condition, but micro-fractures and spallation under lubrication condition. When oil was used for lubrication, the friction coefficient of the sliding pairs and the wear loss of the ceramics were reduced. The wear loss of the MZ coating was less than that of the YZ coating under dry test, but more than that of the YZ coating under lubrication test. The test conditions and the mechanical properties of the ceramic coatings were correlated to the wear performance

WTC2005-63852 SLIDING WEAR BEHAVIOR OF PLASMA SPRAYED ZIRCONIA CERAMIC COATING UNDER DIFFERENT CONDITIONS

ABSTRACT The sliding wear behavior of ZrO 2 -22wt%MgO (MZ) and ZrO 2 -8wt%Y 2 O 3 (YZ) deposited on a cast aluminum alloy with bond layer (NiCrCoAlY) by plasma spray against a SiC ball was investigated under dry and lubrication conditions at room temperature. At all load conditions, the wear mechanisms of the MZ and YZ coatings were almost the same. The wear mechanism involved material transfer and pullout under dry condition, but micro-fractures and spallation under lubrication condition. When oil was used for lubrication, the friction coefficient of the sliding pairs and the wear loss of the ceramics were reduced. The wear loss of the MZ coating was less than that of the YZ coating under dry test, but more than that of the YZ coating under lubrication test. The test conditions and the mechanical properties of the ceramic coatings were correlated to the wear performance

Influence of WS2 Nanopowder Addition on Friction Characteristics of ta-C Coating by FCVA Method

The influence of nano-size WS2 powders on the tribological behavior of ta-C coatings by the filtered cathodic vacuum arc (FCVA) method under boundary lubrication conditions has been investigated. In order to characterize and understand tribological behaviors of nano-size WS2 powders added to the synthetic oil (poly-alpha-olefin 6), lubricants with different mixture ratios, ranging from 2 to 8 wt%, have been prepared. ta-C coatings fabricated by FCVA method showed that the G-peak in the obtained Raman spectrum was shifted from 1520 to 1586 cm−1, indicating the sp3 content increased for samples with the thickness of 156 nm. The average friction coefficient decreased proportionally as the nano-size WS2 compositions increased up to 4 wt% in PAO6. After the friction test, structures and particle sizes of WS2 phases were also precisely characterized by using XRD and SEM