Wear mechanisms of silicon carbide subjected to ultrasonic nanocrystalline surface modification technique (original) (raw)
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Tribological and hydrothermal behaviour of silicon carbide under water lubrication
Wear, 2009
In this study the tribological and hydrothermal behaviour of silicon carbide was examined. No significant reaction layer was found after tribochemical experiments conducted on sintered silicon carbide (SSiC) and after hydrothermal treatment using a hydrothermal diamond anvil cell (HDAC). Mechanical contact of sliding parts induced superficial amorphisation and chemical analysis showed a slight increase in oxygen content within the topmost part of the surface. Static experiments using single-crystal silicon carbide (SCSiC) and a hydrothermal diamond anvil cell revealed an active oxidation mechanism and silica as the result of solution and precipitation.
2011
Double row angular contact ball bearings (DRACBB) are capable of carrying high radial and thrust loads in both directions and need small space comparing to two single row angular contact bearings. A newly developed magnetic clutch of compressor needs higher dynamic load rating without increasing space for bearings. Therefore, Ultrasonic Nanocrystalline Surface Modification (UNSM) technology is applied to bearing raceways in order to improve rolling contact strength and to reduce friction loss. The rolling contact fatigue and friction test specimens which are treated by UNSM technology are performed in order to find proper surface hardness, topology and compressive residual stress. Comparison test of service life and friction coefficient between UNSM-treated and untreated bearings were carried out in the bearing test rig. After UNSM treatment, the friction coefficient was reduced and the service life was extended at room temperature due to the UNSM treatment. Life tests data showed t...
Wear performance of oil lubricated silicon nitride sliding against various bearing steels
Wear, 2003
The selection of bearing steel surfaces for use with silicon nitride rolling elements within hybrid bearings is critical to the performance and life of such components, which have potential applications in advanced high speed aircraft. The wear and friction performance of these combinations is a major factor currently being considered for the next generation hybrid bearings. This paper reports on hybrid bearing contacts that have lubricated Si 3 N 4 elements, which have been loaded against various bearing steels under pure sliding contact conditions on a fully instrumented pin-on-disc wear test rig. The wear and friction performance of Si 3 N 4 has been compared to a baseline case of bearing steel M50 ball sliding against a M50 disc. Both hybrid and steel on steel contacts were lubricated by an aircraft engine oil Mobil Jet II. Wear mechanisms were determined by post-test analysis of the pin wear scars, disc wear surface and wear debris using optical microscopy, surface profilometry and FEG-SEM (scanning electron microscopy). The wear rates of Si 3 N 4 sliding against different bearing steels are ranked by performance and related to their wear mechanisms, hardness and microstructure. Typical sliding contact wear mechanisms were found for the steel on steel combination while Si 3 N 4 sliding against steel showed that transgranular and sub-micron-cracking mechanisms predominate. Evidence of material transfer (steel onto the silicon nitride) was found. Friction values for the various combinations are also reported and found to be substantially lower (µ = 0.04) than bearing steel on bearing steel combinations (µ = 0.17). The disc and pin wear was monitored on-line by an electrostatic wear sensor, LVDT and laser displacement probe, a friction strain gauge, and an infrared thermometer. Correlations between wear rate and charge generation/level, friction, contact temperature, and disc hardness are presented.
Solid/liquid lubrication of ceramics at elevated temperatures
Wear, 1997
This study investigates the effect of solid and liquid lubrication on friction and wear performance of silicon nitride (Si3N4) and cast iron. The solid lubricant was a thin silver film (=2 pm thick) produced on Si3N4 by ion-beam-assisted deposition. A high-temperature polyol-ester-base synthetic oil served as the liquid lubricant. Friction and wear tests were performed with pin-ondisk and oscillating-slider wear test machines at temperatures up to 300°C. Without the silver films, the friction coefficients of Si3N4/Si3N4 test pairs were 0.05 to 0.14, and the average wear rates of Si3N4 pins were =5 x LO-* mm3 N-' m-'. The friction coefficients of SkNJcast iron test pairs ranged fiom 0.08 to 0.1 1, depending on test temperature. The average specific wear rates of cast iron pins were = 3 x lo-' mm3 N" me'. However, simultaneous use of the solid-lubricant silver and synthetic oil on the sliding surfaces reduced friction coefficients to 0.02 to 0.08. Moreover, the wear of Si3N4 pins and silver-coated S&N4 disks was so low that it was difficult to assess by a surface profilometer. The wear rates of cast iron pins were =7 x lo-' mm3 N-' m" up to 250"C, but showed a tendency to increase slightly at much higher temperatures. In general, the test results demonstrated that the solidniquid lubrication of ceramic and/or metallic components is both feasible and effective in .controlling friction and wear. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specifii commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
A Review of Properties, Applications and Presently Study Done on Ceramic Bearings
2014
Severe and precise operating conditions have led to the study and invention of antifriction, negligible lubricant and long life bearing materials. Ceramic and Hybrid Ceramics are one of such bearing materials. The low tendency of adhesion between steel and ceramic components and even less between ceramic parts among themselves provides significant advantage in dry run and under lubricated run. The Technology of hybrid ceramics and ceramic bearings along with their applications and wear rate behavior of different ceramics will be discussed in this paper.
Friction and wear properties of nano-Si3N4/nano-SiC composite under nanolubricated conditions
Journal of Advanced Ceramics, 2016
Friction and wear behaviors of different concentrations of IF-MoS2 nanoparticles in SAE 20W40 were studied. First of all tribological tests with SAE 20W40 + IF-MoS2 were carried out on a four ball wear test machine as per ASTM D 4172 standard to study its wear properties. Detailed friction and wear studies on cylinder liner and piston ring tribopair were conducted on pin-on-block universal tribometer under lubricated conditions of SAE 20W40+ IF-MoS2. These experimental studies were conducted at different operating parameters to ascertain the influence of nanoadditive on friction and wear of cylinder liner and piston ring tribopair. A minimum coefficient of friction of 0.0772 was observed for 0.5 wt% of IF-MoS2 at normal load of 100 N at sliding velocity of 0.03 m/sec. A substantial reduction of 65 % in the wear of cylinder liner and piston ring tribo-pair was also observed when lubricated with SAE 20W40 and 0.5 wt% of IF-MoS2. Scanning electron microscopy and energy dispersive spectrometry analysis of the worn out surfaces was also carried out to find the causes for observed friction and wear behavior.
Wear mechanisms associated with the lubrication of zirconia ceramics in various aqueous solutions
Journal of the European Ceramic Society, 2006
The wear and friction behaviours of self-mated zirconia ceramics were investigated with sliding tests in various aqueous solutions using a reciprocating ball-on-flat testing geometry. The surface charge on the native surfaces and the wear debris were "controlled" by varying the pH of the aqueous solution over a wide range, i.e., between 1 and 13. The aim of this investigation was to determine the wear mechanisms via analyses of the wear debris using SEM, XRD and TEM. Significantly different properties were observed, depending on the testing conditions in the different aqueous solutions; and the nature of the wear debris and the native surfaces was also found to depend on the testing conditions. Regions with high and low levels of wear and friction were detected. The wear was found to vary by as much as an order of magnitude with the change in pH, and under the same conditions the friction was observed to change by a factor of two. In the first region, i.e., under very acidic conditions, chemical dissolution was the predominant effect, resulting in low wear and low friction. At higher pH values, more complex processes consisting of a hydrothermal transformation causing bulk zirconia fracture and the formation of tribochemically assisted wear-debris layers, which subsequently spalled, resulted in rough surfaces with very high wear and high friction. Furthermore, the electrochemical effects in this region caused a wear peak to appear at the isoelectric point. (M. Kalin).
The Abrasive Wear of Non-Oxide Structural Ceramics in Wet Environment
2014
Silicon carbide and silicon nitride are recognized as phases with very good mechanical properties. Many parts of machines and mechanical devices are made of these materials. Particulate composites basing on both mentioned phases have significant potential of properties improvement. The aim of presented work was to check the difference in wear behavior when materials surfaces were attacked by hard, loose particles in wet environment (pulp). Investigations were performed on silicon carbide, silicon nitride and two composites on their matrices. The basic performed test was the Miller Test according to ASTM Standard. The detail microstructural and mechanical characterization of investigated materials was done. Residual stress state caused by coefficients of thermal expansion mismatch was calculated using FEM approach. The second phases for composites were selected to introduce the compressive stress state into the matrix phase. Comparative studies of abrasive wear of “pure” phases and composites performed showed differences between dominating wear mechanisms. Tests results proved that the influence of the second phase presence in the materials was significant for the wear rate.
Wear and friction behaviour of Si3N4 ceramics under diesel and biodiesel lubrication
Journal of Materials Research and Technology, 2013
The wear and friction behaviour of self-mated silicon nitride pairs in lubricated ball-on-flat reciprocating sliding conditions is the subject of the present work, using diesel fuel and soybean biodiesels as lubricants. The results show that the friction coefficient is considerably higher for the diesel fuel than for biodiesels in the stationary regime (about 0.14 and 0.06, respectively). The wear coefficient values are in the range 10 −8-10 −9 mm 3 /N•m, denoting a mild wear regime, in agreement with the high lubricity of these fuels assessed by the ASTM D 6079 standard. The observed wear mechanisms were mainly mechanically dominated, consisting of transgranular and intergranular fractures, and the formation of a tribolayer by plastic deformation of the wear debris.