Effect of Calcining Temperature of Ceramic Powders Prepared from TEOS/Boehmite Sol-Gel on Tribological Behavior of Brake Lining Materials

2010 ◽  
Vol 638-642 ◽  
pp. 950-955
Author(s):  
K.J. Lee ◽  
Y.T. Chen ◽  
H.Z. Cheng ◽  
Jason S.C. Jang ◽  
P.C. Chang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
Sol Gel ◽  
Tribological Performance ◽  
Preparation Process ◽  
Ceramic Powders ◽  
Higher Temperature ◽  
Α Al2o3 ◽  
Brake Lining ◽  
Wear Tests

This study is to investigate tribological behavior of brake lining materials by hot pressing commercial friction powders with ceramic powders prepared by TEOS / boehmite sol-gel. The stoichiometric ratios of TEOS / boehmite sol-gel were kept constant but calcinated at different temperature to fabricate different homemade ceramic powders. The various phases of ceramic powders such as γ-Al2O3, δ-Al2O3, θ-Al2O3, α-Al2O3, cristobalite and mullite were formed during the preparation process starting from TEOS / boehmite sol-gel solution. The XRD observations reveal the final compositions of these homemade powders were strongly related to the calcining temperature. The brake lining specimens made from TEOS / boehmite sol-gel calcinated at higher temperature show better tribological performance. The brake lining specimen with α-Al2O3 and mullite which were transformed from TEOS / boehmite sol-gel calcinated at 1300°C shows the most stable friction coefficient and the lowest mass loss during wear tests.

Phase transformation and characterization of TiO2 and ZrO2 addition in the Li2O–Al2O3-SiO2 gels

1996 ◽  
Vol 11 (10) ◽  
pp. 2611-2615 ◽  
Author(s):  
Ming-Hong Lin ◽  
Moo-Chin Wang
Keyword(s):  
Phase Transformation ◽  
Sol Gel ◽  
Peak Position ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
Ceramic Powders ◽  
Higher Temperature ◽  
Gel Technique ◽  
Dta Curves

Glass-ceramic powders with a composition of Li2O · Al2O3 · 4SiO2 (LAS) have been synthesized by the sol-gel technique using LiOCH3, Al(OC2H5)3, Si(OC2H5)4, Ti(OC2H5)4, and Zr(OC2H5)4 as starting materials and the phase transformation behavior during calcination has been investigated. Differential thermal analysis (DTA), x-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to determine the thermal behavior of the gels. Considering the LAS gels with 6.0 wt. % TiO2 and various wt. % ZrO2 content, and peak position of the β-spodumene phase formation in DTA curves was shifted to a higher temperature when the ZrO2 content was increased. The activation energy of β-spodumene crystallization was 283.8 kcal/mol for LAS gels with 6.0 wt. % TiO2 and 2.0 wt. % ZrO2. Unlike foregoing studies for LAS gels, during calcination of the dried LASTZ gels from 800 °C to 1200 °C neither β-eucryptite nor γ-spodumene was noted to be present. The crystallized phases comprised of β-spodumenes as the major phase and rutile (TiO2) together with zirconia (ZrO2) are precipitated as minor phases.

scholarly journals Tribological Behavior Analysis of the ISO 5832-1 Austenitic Stainless-Steel Treated by Optical Fiber Laser Used for Biomedical Applications

2019 ◽  
Vol 8 (2) ◽  
pp. 91-96
Author(s):  
Marcelo De Matos Macedo ◽  
Ronaldo Câmara Cozza
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Austenitic Stainless Steel ◽  
Optical Fiber ◽  
Abrasive Wear ◽  
Fiber Laser ◽  
Tribological Behavior ◽  
Laser Frequency ◽  
Wear Volume ◽  
Wear Tests

The present work analyzed the influence of an optical fiber laser surface treatment process on the tribological behavior of the ISO 5832-1 austenitic stainless-steel, basing on the wear volume and friction coefficient. Specimen of this biomaterial were treated by alternating the laser frequency, in order to find out a condition that improves its tribological resistance. Ball-cratering micro-abrasive wear tests were carried out with a test ball of AISI 316L stainless-steel, used as counter-body, and an abrasive slurry prepared with abrasive particles of black silicon carbide (SiC) and distilled water. The micro-abrasive wear tests results indicated that: i) the hardness of the ISO 5832-1 austenitic stainless-steel increased as a function of the laser frequency, decreasing, consequently, the wear volume, as predicted by Archard’s Law; ii) the friction coefficient did not present a proportional behavior with the increase of the optical fiber laser frequency; iii) the best condition to improve the wear resistance of the ISO 5832-1 austenitic stainless-steel was obtained adopting an optical fiber laser frequency of 350 kHz, being reported the lower wear volume.

Influence of Additive Chemistry on the Tribological Behavior of Steel/Copper Friction Pairs

2021 ◽  
Author(s):  
Weimin Li ◽  
Huaigang Su ◽  
Yunlong Chen ◽  
Rui Ma ◽  
Gaiqing Zhao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Boundary Lubrication ◽  
High Performance ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Copper Oxides ◽  
Wear Volume ◽  
Base Oil ◽  
Lubrication Film ◽  
Order Of Magnitude

Abstract The tribological behavior of boundary lubrication is largely dominated by the anti-wear additives. Here five different anti-wear additives were selected and their tribological properties for a steel-copper contact were investigated. It was found that the tribological performance are highly depending on the anti-wear additive chemistry which determines activity, element compositions of the additive. An amine phosphate anti-wear additive AW 316 exhibit best tribological performance with the lowest mean friction coefficient of 0.082 and smallest wear volume which is more than one order of magnitude smaller than base oil. The friction-reducing order of the tested anti-wear additives are AW 316 > ZDDP > 353 > TCP > [P8888][DEHP] while anti-wear showed similar trend. In addition, the tribological mechanism of AW 316 were also discussed based on surface analysis results, and it was found that an even boundary lubrication film of 10–15 nm which was composed of copper oxides, phosphates, amines was formed on the copper disc and is responsible for its outstanding tribological performances. This study provides fundamental insights of the compatibilities among steel-copper friction pairs and suitable anti-wear additives, which can be beneficial for the development of high performance used for steel-copper friction pairs.

The structure properties and tribological behavior of the ionic liquid–polyimide composite films under high-vacuum environment

2016 ◽  
Vol 29 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Mei Lv ◽  
Feng Han ◽  
Qihua Wang ◽  
Tingmei Wang ◽  
Yongmin Liang
Keyword(s):  
Ionic Liquid ◽  
Friction Coefficient ◽  
Tribological Behavior ◽  
High Vacuum ◽  
Composite Films ◽  
Film Surface ◽  
Tribological Performance ◽  
Steel Ball ◽  
High Vacuum Environment ◽  
Structure Properties

Ionic liquid (IL) can be used as external or internal lubricant. The tribological performance of polyimide (PI)–steel contact surface driven by IL lubricant was investigated using a ball-on-disk tribometer in high-vacuum environment. The experimental results indicated that IL as the external lubricant could obviously decrease the friction coefficient of PI from 0.41 to 0.01 and corrode the surface of steel ball. As internal lubricant, some IL/PI composite films were prepared, and the structure properties and tribological behavior were investigated. IL can be uniformly dispersed in the polymer and could make film surface more hydrophilic along with the increasing content of IL in PI. The IL/PI composite film with 1% content of IL has the lowest friction coefficient and causes the least damage against the steel ball.

Effect of nanoparticles on the tribo-layers and the tribology of a steel-on-steel couple

2018 ◽  
Vol 233 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Kangmin Chen ◽  
Wei Jiang ◽  
Xianghong Cui ◽  
Shuqi Wang
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Wear Rates ◽  
Cover Type ◽  
Sliding Interface ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel ◽  
Mixture Additives

The tribological behavior and tribo-layers of AISI 1045 steel sliding against 52100 steel were investigated in the case of supplying MoS2, Fe2O3, and their mixtures onto the sliding interface. When nanoparticles were supplied, tribo-layers were formed on the worn surfaces. The tribological behavior of the sliding pair depended on the characteristics of tribo-layers, which were decided by different nanoparticles. As the additives—especially the ones containing MoS2—were supplied onto the sliding interface, the wear rates and friction coefficients of both 1045 steel and 52100 steel were markedly decreased to extremely low values, approaching zero and marginally undulated with the increase in load. Single-component Fe2O3 nanoparticles markedly reduced the wear rate of 1045 steel with slightly increased friction coefficient, but its decreased extent was merely half of that of the additives containing MoS2. The improvement of the tribological performance of steels was attributed to the formation of protective tribo-layers. The addition of pure Fe2O3 resulted in the formation of insert-type tribo-layers, while cover-type tribo-layers were formed by the addition of the mixture additives of Fe2O3+MoS2 and pure MoS2. The cover-type tribo-layers provided more protective and lubricative functions than that of the insert-types.

Microstructure and Dry Sliding Tribological Behavior of Microarc Oxidation Coating Formed on Ti6Al4V against Steel

2007 ◽  
Vol 336-338 ◽  
pp. 1734-1736
Author(s):  
Ya Ming Wang ◽  
Ting Quan Lei ◽  
De Chang Jia ◽  
Yu Zhou ◽  
Jia Hu Ouyang
Keyword(s):  
Friction Coefficient ◽  
Ceramic Coating ◽  
Tribological Behavior ◽  
Gradual Increase ◽  
Microarc Oxidation ◽  
Anatase Tio2 ◽  
Grain Structure ◽  
Compact Layer ◽  
Oxidation Wear ◽  
Wear Tests

A nanostructured TiO2 dominated ceramic coating was fabricated on Ti6Al4V by microarc oxidation (MAO). The coating with about 30 μm thickness is porous in the outer layer and compact in the inner layer, mainly composed of rutile and a small amount of anatase TiO2, both in nano grain structure. The hardness and elastic modulus of the compact layer in the coating are about 8.5 GPa and 87.4 GPa. The adhesion strength is about 70MPa. The friction coefficient of the polished coating sliding against GCr15 steel is as low as 0.2, which is clearly superior to that of the unpolished one. This is attributed to the low surface roughness. However, the oxidation wear mechanism occurring at the later stage of wear tests leads to a gradual increase of friction coefficient.

scholarly journals A review of the bio-tribology of medical devices

Friction ◽  
2021 ◽  
Author(s):  
Xiaogang Zhang ◽  
Yali Zhang ◽  
Zhongmin Jin
Keyword(s):  
Service Life ◽  
Medical Devices ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Dental Restoration ◽  
Surgical Instruments ◽  
Cardiovascular Devices ◽  
Artificial Joints ◽  
Future Developments ◽  
Fixation Devices

AbstractNumerous medical devices have been applied for the treatment or alleviation of various diseases. Tribological issues widely exist in those medical devices and play vital roles in determining their performance and service life. In this review, the bio-tribological issues involved in commonly used medical devices are identified, including artificial joints, fracture fixation devices, skin-related devices, dental restoration devices, cardiovascular devices, and surgical instruments. The current understanding of the bio-tribological behavior and mechanism involved in those devices is summarized. Recent advances in the improvement of tribological properties are examined. Challenges and future developments for the prospective of bio-tribological performance are highlighted.

scholarly journals Spray‐dried sol‐gel glass‐ceramic powders based on the tunable thermal expansion of quartz and keatite solid solutions

2021 ◽  
Author(s):  
Alessio Zandona ◽  
Gundula Helsch ◽  
Aurina Martínez Arias ◽  
Alfred P. Weber ◽  
Joachim Deubener
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Ceramic Powders ◽  
Spray Dried

Effect of copper incorporation on phase transformation behavior of electroless nickel–phosphorous coating and its effect on the tribological behavior

2020 ◽  
pp. 146442072098160
Author(s):  
Abhijit Biswas ◽  
Suman Kalyan Das ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Tribological Behavior ◽  
Electroless Nickel ◽  
Two Phase ◽  
Microstructural Changes ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Higher Temperature ◽  
Effect Of Copper

The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings are heat-treated at temperatures ranging between 200°C and 800 °C and for 1–4 h duration. Ni–P–Cu coatings exhibit two-phase transformations in the temperature range of 350–450 °C and the resulting microstructural changes are found to significantly affect their thermal stability and tribological attributes. Hardness of the coating doubles when heat-treated at 452 °C, due to the formation of harder Ni3P phase and crystalline NiCu. Better friction and wear performance are also noted upon heat treatment of the coating at the phase transformation regime, particularly at 400 °C. Wear mechanism is characterized by a mixed adhesive cum abrasive wear phenomena. Heat treatment at higher temperature (600 °C and above) and longer duration (4 h) results in grain coarsening phenomenon, which negatively influences the hardness and tribological characteristics of the coating. Besides, diffusion of iron from the ferrous substrate as well as greater oxide formation are noticed when the coating is heat-treated at higher temperatures and for longer durations (4 h).

scholarly journals Sodium Solid Electrolytes: NaxAlOy Bilayer-System Based on Macroporous Bulk Material and Dense Thin-Film

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 854
Author(s):  
Antonia Hoppe ◽  
Cornelius Dirksen ◽  
Karl Skadell ◽  
Michael Stelter ◽  
Matthias Schulz ◽  
...  
Keyword(s):  
Pore Size ◽  
Bulk Material ◽  
Sol Gel ◽  
Dense Layer ◽  
X Ray Diffraction ◽  
Bilayer System ◽  
Step Procedure ◽  
Short Circuits ◽  
Α Al2o3 ◽  
Sol Gel Synthesis

A new preparation concept of a partially porous solid-state bilayer electrolyte (BE) for high-temperature sodium-ion batteries has been developed. The porous layer provides mechanical strength and is infiltrated with liquid and highly conductive NaAlCl4 salt, while the dense layer prevents short circuits. Both layers consist, at least partially, of Na-β-alumina. The BEs are synthesized by a three-step procedure, including a sol-gel synthesis, the preparation of porous, calcined bulk material, and spin coating to deposit a dense layer. A detailed study is carried out to investigate the effect of polyethylene oxide (PEO) concentration on pore size and crystallization of the bulk material. The microstructure and crystallographic composition are verified for all steps via mercury intrusion, X-ray diffraction, and scanning electron microscopy. The porous bulk material exhibits an unprecedented open porosity for a NaxAlOy bilayer-system of ≤57% with a pore size of ≈200–300 nm and pore volume of ≤0.3 cm3∙g−1. It contains high shares of crystalline α-Al2O3 and Na-β-alumina. The BEs are characterized by impedance spectroscopy, which proved an increase of ionic conductivity with increasing porosity and increasing Na-β-alumina phase content in the bulk material. Ion conductivity of up to 0.10 S∙cm−1 at 300 °C is achieved.

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