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.

Effect of Varying Wt% of TiC on Mechanical and Wear Properties of RZ5-TiC In-Situ Composite

2018 ◽  
Vol 8 (2) ◽  
pp. 45-56 ◽  
Author(s):  
Deepak Mehra ◽  
M.M. Mahapatra ◽  
S. P. Harsha
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Wear Test ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Tic Particle ◽  
Mechanical And Microstructural Properties ◽  
Sliding Distance

The purpose of this article is to enhance the mechanical properties and wear resistance of the RZ5 alloy used in the aerospace application by adding TiC particles. The present study discusses processing of in-situ RZ5-TiC composite fabricated by self-propagating high temperature (S.H.S.) method and its wear behavior. The effects of TiC particle on mechanical and microstructural properties of the composite are studied. The wear test is performed by varying the sliding distance and applied load. The composite is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results exhibited the properties like strength and hardness of RZ5-10wt%TiC composite has been increased considerably, while grain size is decreased as compared to the RZ5 alloy. The fractography indicated mixed mode (quasi-cleavage and ductile feature) failure of the composites. The wear results showed improvement in wear resistance of the composite. The FESEM showed dominate wear mechanisms are abrasion, ploughing grooves.

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.

scholarly journals The Wear Behavior of the Laser Cladded Ti-Al-Si Composite Coatings on Ti-6Al-4V Alloy with Additional TiC

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4567
Author(s):  
Ran Liu ◽  
Xianting Dang ◽  
Yuan Gao ◽  
Tao Wu ◽  
Yuanzhi Zhu
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Cladding Process ◽  
Fine Microstructure ◽  
The Coefficient Of Friction ◽  
Formation Of Cracks ◽  
Different Content

In this study, the Ti-Al-Si + xTiC (x = 0, 2, 6, 10 wt.%) composite coatings, each with a different content of TiC were fabricated on a Ti-6Al-4V alloy by laser surface cladding. The microstructure of the prepared coatings was analyzed by the scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The microhardness and the wear resistance of these coatings were also evaluated. The results show that α-Ti, Ti3Al, Ti5Si3, TiAl3, TiAl, Ti3AlC2 and TiC particles can be found in the composites. The microstructure can obviously be refined by increasing the content of TiC particles, while the microhardness increases and the coefficient of friction decreases. The Ti-Al-Si-6TiC composite shows the best wear resistance, owing to its relatively fine microstructure and high content of TiC particles. The microhardness of this coating is 5.3 times that of the substrate, while the wear rate is only 0.43 times. However, when the content of TiC was up to 10 wt.%, the original TiC could not be dissolved completely during the laser cladding process, leading to formation of cracks on the coatings.

scholarly journals Tribological Performance of Graphite Nanoplatelets Reinforced Al and Al/Al2O3 Self-Lubricating Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1183
Author(s):  
Emad Omrani ◽  
Afsaneh Dorri Moghadam ◽  
Ashish K. Kasar ◽  
Pradeep Rohatgi ◽  
Pradeep L. Menezes
Keyword(s):  
Electron Microscopy ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Defect Formation ◽  
Multilayer Graphene ◽  
Graphite Nanoplatelets ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al2o3 Composite ◽  
The Coefficient Of Friction

In the present work, the effect of graphite nanoplatelets (GNPs) on tribological properties of the aluminum (Al), and Al/alumina (Al2O3) composite are studied. GNPs are multilayer graphene sheets which were used as a solid lubricant material. Two sets of composites, Al/GNPs and Al/GNPs/Al2O3 with varying amounts of reinforcements, were synthesized by powder metallurgy that involves cold compaction followed by hot compaction. The hardness of the composites increased with the addition of GNPs and Al2O3. The Al/GNPs composite with 1 wt.% of GNPs (Al/1GNPs) showed a 20% increase in hardness whereas Al/GNPs/ Al2O3 composite with 1 wt.% GNPs and 2 wt.% Al2O3 (Al/1GNPs/2Al2O3) showed 27% increases in hardness compared to the pure Al. The coefficient of friction measured at 20 N was observed to be 22% and 53% lesser for Al/1GNPs and Al/1GNPs/2Al2O3, respectively, compared to corresponding alloys without graphene Al. The X-ray diffraction and scanning electron microscopy analysis revealed the presence of GNPs at the worn surface after the tribology tests. The wear rate was also reduced significantly. In comparison with pure Al, the Al/1GNPs and Al/1GNPs/2Al2O3 composites resulted in 5- and 20-times lesser wear rate, respectively. The addition of Al2O3 caused reduction in wear rate due to higher hardness and load carrying ability, whereas composites with more than 1 wt.% GNPs showed higher wear rate due to lower hardness and higher porosity. The Al/1GNPs/2Al2O3 composite exhibited the least coefficient of friction (0.2–0.25) and wear rate (1 × 10−6–4 × 10−6 mm3/N.m) compared to other GNPs and Al2O3 reinforced Al composites. The worn surfaces were further analyzed to understand the wear mechanism by Raman spectroscopy, transmission electron microscopy, and x-ray diffraction to detect the Al4C3 phase formation, chemical bonding, and defect formation in graphene.

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.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

In-situ Investigation of Bainite Formation with fast X-Ray Diffraction (iXRD)

2017 ◽  
Vol 72 (6) ◽  
pp. 355-364
Author(s):  
A. Kopp ◽  
T. Bernthaler ◽  
D. Schmid ◽  
G. Ketzer-Raichle ◽  
G. Schneider
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Investigation
Sign in / Sign up

Export Citation Format

Share Document