Exploring Failure Mechanisms of Lubricated 52100 Steel Contacts in High Vacuum and Dry Air

1988 ◽  
Vol 140 ◽  
Author(s):  
Michael T. Dugger ◽  
Yip-Wah Chung
Keyword(s):  
Normal Load ◽  
High Vacuum ◽  
X Ray ◽  
Dry Air ◽  
Synthetic Hydrocarbon ◽  
The Coefficient Of Friction ◽  
Contact Life ◽  
Steel Balls ◽  
Pin On Disk

AbstractA vacuum chamber was designed for studying tribological properties of materials under pressures of 5xlO8 Torr to one atmosphere. The chamber is equipped with a pin-on-disk tribometer, in-situ Auger\X-ray photoelectron spectroscopies, a sputter-ion gun and a windowless solid-state X-ray detector. In this paper, we present results of a study using 52100 steel balls sliding on flat disks of the same material in vacuum and in dry air as a function of normal load. The contacts were lubricated with a synthetic hydrocarbon oil (poly-a-olefin). Failure is defined as the point at which the coefficient of friction increases rapidly above the steady state value.As expected, failure occurs much sooner in vacuum than in dry air. Surface analysis (Auger and XPS) shows direct evidence of the occurrence of high temperature flashes on the surface, which allows the formation and maintenance of a thick oxide in the presence of an adequate supply of oxygen. In addition, a brown film is formed in the vicinity of the wear track for tests performed in dry air, while this film is absent in vacuum. The brown film appears to be a combination of iron oxide and oxidized hydrocarbon from XPS measurements. Results of these studies suggest that the maintenance of an oxide is associated with extended contact life in these studies.

scholarly journals Friction and Wear Behavior of Alumina Composites with In-Situ Formation of Aluminum Borate and Boron Nitride

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4502
Author(s):  
Ashish K. Kasar ◽  
Pradeep L. Menezes
Keyword(s):  
Boron Nitride ◽  
Coefficient Of Friction ◽  
Wear Behavior ◽  
Hardness Measurement ◽  
Aluminum Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Steel Balls

Wear and friction properties of Al2O3 composite reinforced with in-situ formed aluminum borate (9Al2O3·2B2O3) and hexa-boron nitride (h-BN) have been investigated. The initial constituents for the composites were Al2O3, AlN, and H3BO3. The H3BO3 was used as a source of B2O3, where B2O3 reacted with AlN and Al2O3 to form in-situ h-BN and 9Al2O3·2B2O3. Based on the thermodynamic calculation and phase transformation, four different compositions were selected. First, the powders were mixed by ball milling followed by compaction at 10 MPa. The compacted pellets were sintered at 1400 °C in vacuum. The composites were characterized using X-ray diffraction followed by hardness measurement and reciprocating sliding test against alumina and steel balls. The X-ray diffraction results revealed the formation of in situ phases of 9Al2O3·2B2O3 and h-BN that improved the tribological properties. By comparing the tribological performance of different composites, it was found that the hard 9Al2O3·2B2O3 phase maintains the wear resistance of composites, whereas the coefficient of friction is highly dependent on the counter ball. Against alumina ball, the lowest coefficient of friction was observed for the composites with maximum h-BN concentration and minimum aluminum borate concentration, whereas the opposite trend was observed against the steel ball.

Incorporation and Role of Nitrogen During Oxynitridation of Silicon Studied by Photoelectron Spectroscopy

1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Gaseous Mixtures ◽  
X Ray ◽  
Initial Stage ◽  
Thermal Stability Of

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.

Study of Tribological Properties of Multilayer Ti/TiN Coating Containing Stress Absorbing Layers

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Amod Kashyap ◽  
A. P. Harsha ◽  
Harish C. Barshilia ◽  
Venkataramana Bonu ◽  
Praveen Kumar V. ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Wear Behavior ◽  
Multilayer Coating ◽  
Considerable Change ◽  
Wear Volume ◽  
Significant Drop ◽  
X Ray ◽  
Paraffin Oil ◽  
The Coefficient Of Friction ◽  
Steel Balls

Abstract Titanium (Ti)/titanium nitride (TiN) ultrathin multilayer coating was deposited on 100Cr6 substrates to investigate the friction and wear behavior in the presence of paraffin oil as a lubricant. The coating architecture was designed by adding thick stress absorbing layers (SAL ∼320 nm) in between the ultrathin Ti/TiN (3.5/4 nm) multilayer structure. The SAL reduces the residual stress in the coating. The coating had a NaCl type of structure, and X-ray diffraction (XRD) results showed the preferential crystallographic orientation of TiN along [111] direction. The tribological properties of the nanostructured coating were evaluated under reciprocating sliding conditions at varying loads (2 and 7 N), and temperature (30 and 100 °C) against 100Cr6 steel balls using paraffin oil as a lubricant. There was no considerable change in the coefficient of friction (COF) at different testing parameters. However, there was a significant drop in wear volume at high-temperature testing conditions. The worn tracks were analyzed for their morphology and elemental composition through scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and Raman spectroscopy.

A Mechanism of Sliding on the Nanometer-Thick Ag Layers

2005 ◽  
Author(s):  
F. Honda ◽  
M. Goto
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
High Vacuum ◽  
High Energy ◽  
Thin Layers ◽  
Ultra High Vacuum ◽  
Wear And Friction ◽  
Thickness Measurements

Tribological performance of sub-nano to nanometer-thick Ag layers deposited on Si(111) have been examined to understand the role of surface thin layers to the wear and friction characteristics. The slider was made of diamond sphere of 3 mm in radius. Sliding tests were carried out in an ultra-high vacuum environment (lower than 4 × 10−8 Pa) and analyzed in-situ by Auger electron spectroscopy (AES) for the quantitative thickness-measurements, by reflection high-energy electron diffraction (RHEED) to clarify the substrate cleanliness and crystallography of the Ag films, and by scanning probe microscopy (SPM) for the morphology of the deposited/slid film surfaces. As the results, a minimum of the friction coefficient 0.007 was observed from the film thickness range of 1.5–10 nm, and exactly no worn particles were found after 100 cycles of reciprocal sliding. Results have directly indicated that solid Ag(111) sliding planes allowed to reduce the friction coefficient very low without any detectable wear particles, and Ag nanocrystallites in Ag polycrystalline layers increase the size to 20–40 nm order, during sliding. The friction coefficient was slightly dependent to the normal load. Results were discussed on the role of the surface atoms to the friction, and a mechanism of sliding on Ag thin layers.

Study on the effects of nano-aluminum-oxide particulates on mechanical and tribological characteristics of chopped carbon fiber reinforced epoxy composites

2015 ◽  
Vol 231 (4) ◽  
pp. 403-422 ◽  
Author(s):  
Kali Dass ◽  
SR Chauhan ◽  
Bharti Gaur
Keyword(s):  
Carbon Fiber ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Epoxy Composites ◽  
Specific Wear Rate ◽  
Tribological Characteristics ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Mechanical And Tribological Characteristics

An experimental study has been carried out to investigate the mechanical and tribological characteristics of chopped carbon fiber (CCF) reinforced epoxy composites filled with nano-Al2O3 particulates, as a function of fiber and filler contents. The experiments were conducted using a pin-on-disc wear test apparatus under dry sliding conditions. The coefficient of friction and specific wear rate of these composites was determined as a function of applied normal load, sliding velocity, sliding distance, and reinforcement content. The tensile, flexural, and compression strengths of ortho cresol novalac epoxy and chopped carbon fiber (OCNE/CCF) filled composites are found to be within the ranges of 48–58.54 MPa, 115–156.56 MPa, and 48–61.15 MPa. Whereas the tensile, flexural, and compression strengths of OCNE/CCF/Al2O3-filled composites are found to be within the ranges of 96–110 MPa, 176–204.66 MPa, and 72–85.65 MPa, respectively. It has been observed that the coefficient of friction decreases and specific wear rate increases with increase in the applied normal loads. Further increases in the fiber (6 wt%) and particle (3 wt%) contents in the epoxy matrix resulted in a decrease of both the mechanical and tribological properties, but remains above that of the CCF reinforced epoxy composites. The worn surfaces of composites were examined with scanning electron microscopy equipped with energy dispersion X-ray analyzer and X-ray diffraction analysis technique to investigate the wear mechanisms.

scholarly journals The Effect of Surface Texture on Lubricated Fretting

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4886
Author(s):  
Agnieszka Lenart ◽  
Pawel Pawlus ◽  
Andrzej Dzierwa ◽  
Slawomir Wos ◽  
Rafal Reizer
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texture ◽  
Friction And Wear ◽  
Normal Load ◽  
Disc Surface ◽  
The Coefficient Of Friction ◽  
42Crmo4 Steel ◽  
Ball Diameter ◽  
Steel Balls ◽  
Effect Of Surface

Experiments were conducted using an Optimol SRV5 tester in lubricated friction conditions. Steel balls from 100Cr6 material of 60 HRC hardness were placed in contact with 42CrMo4 steel discs of 47 HRC hardness and diversified surface textures. Tests were carried out at a 25–40% relative humidity. The ball diameter was 10 mm, the amplitude of oscillations was set to 0.1 mm, and the frequency was set to 80 Hz. Tests were performed at smaller (45 N) and higher (100 N) normal loads and at smaller (30 °C) and higher (90 °C) temperatures. During each test, the normal load and temperature were kept constant. We found that the disc surface texture had significant effects on the friction and wear under lubricated conditions. When a lower normal load was applied, the coefficient of friction and wear volumes were smaller for bigger disc surface heights. However, for a larger normal load a higher roughness corresponded to a larger coefficient of friction.

scholarly journals TEXS: in-vacuum tender X-ray emission spectrometer with 11 Johansson crystal analyzers

2020 ◽  
Vol 27 (3) ◽  
pp. 813-826 ◽  
Author(s):  
Mauro Rovezzi ◽  
Alistair Harris ◽  
Blanka Detlefs ◽  
Timothy Bohdan ◽  
Artem Svyazhin ◽  
...  
Keyword(s):  
Vacuum Chamber ◽  
Solid Angle ◽  
High Vacuum ◽  
Core Hole ◽  
Innovative Design ◽  
X Ray ◽  
The Core ◽  
First Results ◽  
Sufficient Space

The design and first results of a large-solid-angle X-ray emission spectrometer that is optimized for energies between 1.5 keV and 5.5 keV are presented. The spectrometer is based on an array of 11 cylindrically bent Johansson crystal analyzers arranged in a non-dispersive Rowland circle geometry. The smallest achievable energy bandwidth is smaller than the core hole lifetime broadening of the absorption edges in this energy range. Energy scanning is achieved using an innovative design, maintaining the Rowland circle conditions for all crystals with only four motor motions. The entire spectrometer is encased in a high-vacuum chamber that allocates a liquid helium cryostat and provides sufficient space for in situ cells and operando catalysis reactors.

Investigation of Ti3SiC2 MAX Phase Formation onto N-Type 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 845-848 ◽  
Author(s):  
Alexia Drevin-Bazin ◽  
Jean François Barbot ◽  
Thierry Cabioc’h ◽  
Marie France Beaufort
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
High Vacuum ◽  
Max Phase ◽  
Vacuum System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Transmission Electron

In this study, investigations on MAX phase Ti3SiC2 formation to n-type 4H-SiC substrates and its ohmic-behaved are reported. Ti-Al layers were deposited onto SiC substrates at room temperature by magnetron sputtering in high vacuum system. Thermal annealing at 1000°C in Ar atmosphere were performed to allow interdiffusion processes. X-ray diffraction and High Resolution Transmission Electron Microscopy reveal that a Ti3SiC2 contact, in perfect epitaxy with 4H-SiC substrate, is so-obtained. In situ annealing experiment underlines the evolution of Ti-Al contact microstructure versus temperature. The evolution of contact system from Schottky to Ohmic behaved is observed by I-V measurements for annealing temperatures larger than 700°C.

A compact UHV X-ray diffractometer for studying surfaces and interfaces

1998 ◽  
Vol 5 (3) ◽  
pp. 887-889
Author(s):  
Yoshikazu Fujii ◽  
Takeshi Nakamura ◽  
Mutsumi Kai ◽  
Kentaroh Yoshida
Keyword(s):  
High Vacuum ◽  
Layer Growth ◽  
Ultra High Vacuum ◽  
Layer By Layer ◽  
Crystal Surfaces ◽  
X Ray ◽  
Surfaces And Interfaces ◽  
Optical Table ◽  
Specimen Orientation

A compact ultra-high-vacuum (UHV) X-ray diffractometer for surface glancing X-ray scattering has been constructed. All the equipment, including a rotating-anode source of 18 kW and a UHV specimen chamber, is arranged on one optical table of dimensions 70 × 90 cm. The specimen chamber is 14 cm in diameter and 20 cm high and can be evacuated up to 3 × 10−8 Pa. It is equipped with two Be windows of thicknesses 0.2 and 0.4 mm. Specimen orientation in the vacuum is controlled from the outside. The specimen can be heated up to 773 K. The chamber has two evaporation cells and can be used for in situ observations of growing crystal surfaces. Using this instrument, we observed a mechanically polished Ag surface and successfully made an in situ observation of the layer-by-layer growth of a PbSe(111) surface. The instrument will be useful for preliminary experiments using laboratory sources, prior to final measurements at synchrotron radiation facilities.

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