Improved tribology performances of copper graphite (Cu/C) using a phosphorized oxidization surface obtained with tricresyl phosphate (TCP)

2021 ◽  
Vol 73 (7) ◽  
pp. 1028-1036
Author(s):  
Hailin Lu ◽  
Feng Hu ◽  
Qi Liu ◽  
Yihong Li
Keyword(s):  
High Temperature ◽  
Wear Rate ◽  
Oxide Film ◽  
Film Surface ◽  
Bearing Steel ◽  
Liquid Oxygen ◽  
Rocket Engines ◽  
Tricresyl Phosphate ◽  
Content Type ◽  
Lubrication Performance

Purpose Copper-graphite (Cu/C) is a type of seal material that has been widely used in liquid rocket engines and with normal metal pairs, has a high wear rate under liquid oxygen lubrication. In this study, bearing steel disks were subjected to a high-temperature oxidization and phosphating progress to create an oxidized tricresyl phosphating film (OTCP) film, using tricresyl phosphate (TCP) as the phosphating solvent. It is hoped that the surface wear rate and friction coefficient can be reduced by this method. Design/methodology/approach This study aim to form an anti-wear film on the surface of bearing steel, which can significantly improve the lubrication performance of Cu/C and bearing steel. The surfaces of bearing steel disks were dried to remove surface water and then put on a heating plate with a magnetic stirrer and a blue glazed oxide film obtained by heating the disks in the air at 200°C for 1 h. To create the OTCP film, bearing steel disks with a blue glazed oxide film were cleaned ultrasonically three times in ethanol and then placed in baths of TCP. After heating for 2 h at 120°C, excess TCP liquid was removed from the disks using ethanol, leaving an OTCP film on the disk surface. Findings It was found that steel coated with an OTCP film demonstrated better tribological performance (lower coefficient of fiction and wear rate) when pairing with Cu/C than either oxidized or untreated bearing steel. Additional chemical reactions occur when the oxide disk is immersed in TCP and the FePO4 film is formed after heating. Additionally, the OTCP film coated steel displayed good corrosion resistance, as confirmed by electrochemical corrosion tests. This finding demonstrates the potential for this process in the aerospace industry. Originality/value The preparation of OTCP films via high-temperature oxidization and phosphating of bearing steel was demonstrated, with the tribological properties of the OTCP film being investigated alongside those of the original surface and an oxidized film surface. The fabrication of OTCP films is easily scaled up and exhibits significant advantages as a new technology for applications in mechanical contact seal lubrication.

Tribological performance, electrochemical behavior and biocompatibility of high-temperature gas-nitrided Ti6Al4V alloy

2018 ◽  
Vol 70 (8) ◽  
pp. 1536-1544 ◽  
Author(s):  
Wen-Hsien Kao ◽  
Yean-Liang Su ◽  
Jeng-Haur Horng ◽  
Shu-Er Yang
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Wear Rate ◽  
Tribological Properties ◽  
Design Methodology ◽  
Tribological Performance ◽  
Ti6al4v Alloy ◽  
Content Type ◽  
Polarization Test ◽  
High Temperature Gas

Purpose This paper aims to investigate the tribology, corrosion resistance and biocompatibility of high-temperature gas-nitrided Ti6Al4V alloy. Design/methodology/approach The tribological properties were studied by reciprocating wear tester. The corrosion resistance was evaluated by using potentiodynamic polarization test. The purified mouse leukaemic monocyte macrophage cells are used to investigate the biocompatibility. Findings The results show that the nitriding treatment leads to a significant improvement in the hardness and tribological properties of Ti6Al4V alloy. Specifically, compared to untreated Ti6Al4V, the hardness increases from 3.24 to 9.02 GPa, while the wear rate reduces by 12.5 times in sliding against a Ti6Al4V cylinder and 19.6 times in sliding against a Si3N4 ball. Furthermore, the nitriding treatment yields an improved corrosion resistance and a biocompatibility similar to that of untreated Ti6Al4V. Originality/value The nitrided Ti6Al4V alloy is an ideal material for the fabrication of load-bearing artificial implants.

The microstructure and high-temperature tribology behavior of high boron HSS under different heat treatments

2019 ◽  
Vol 71 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Zhentao Yuan ◽  
Yehua Jiang ◽  
Lu Li ◽  
Zulai Li
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Engineering Application ◽  
Heat Treatments ◽  
Quenching Temperature ◽  
Content Type ◽  
X Ray ◽  
High Boron ◽  
High Temperature Tribology

Purpose The purpose of this paper is to study the microstructure and the high-temperature tribology behavior of a high-speed steel (HSS) roller material with boron as the main alloy element under different heat treatments, aiming to provide some theoretical references for its engineering application. Design/methodology/approach The samples of high boron HSS were quenched at 900°C, 1,000°C, 1,050°C and 1,150°C. The microstructure, composition and phase composition of this new HSS were analyzed by OM, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometer. The surface hardness and the tribology behavior under high temperature were measured by Rockwell hardness tester and the high-temperature friction and wear tester. The wear morphology was observed by SEM. Findings The high-temperature friction coefficient and the relative wear rate of the high boron HSS decrease first, then increase with the rise of the quenching temperature. When the quenching temperature is 1,050°C, both the friction coefficient (0.425) and the relative wear rate (79 per cent) are the smallest. Under the high-temperature friction environment, the high boron HSS mainly includes oxidation wear, adhesive wear and abrasive wear. The effect of abrasive wear is weakened gradually with the rise of the quenching temperature, and the high-temperature wear resistance is improved significantly. Compared with the traditional roll materials, the service life of the new high boron HSS is greatly improved. It is an ideal substitute product for the high chromium cast iron roll. Originality/value The boron element replaces other precious metals in high boron HSS, which has the advantage of low production cost, and it has a wide application in the field of roll materials. In this paper, the microstructure, the transformation of hard phases and the high-temperature tribology behavior of this new high boron HSS under different heat treatments were studied, aiming to provide some theoretical references for its engineering application.

scholarly journals High-Temperature Oxidation Behavior of AlTiNiCuCox High-Entropy Alloys

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5319
Author(s):  
Junfeng Wang ◽  
Qiaobai He ◽  
Guanqi Liu ◽  
Qi Zhang ◽  
Guotan Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Film Surface ◽  
High Entropy Alloys ◽  
Temperature Oxidation ◽  
High Entropy ◽  
High Temperature Oxidation Behavior ◽  
Oxide Film Surface

In this study, the high-temperature oxidation behavior of a series of AlTiNiCuCox high-entropy alloys (HEAs) was explored. The AlTiNiCuCox (x = 0.5, 0.75, 1.0, 1.25, 1.5) series HEAs were prepared using a vacuum induction melting furnace, in which three kinds of AlTiNiCuCox (x = 0.5, 1.0, 1.5) alloys with different Co contents were oxidized at 800 °C for 100 h, and their oxidation kinetic curves were determined. The microstructure, morphology, structure, and phase composition of the oxide film surface and cross-sectional layers of AlTiNiCuCox series HEAs were analyzed using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD). The influence of Co content on the high-temperature oxidation resistance of the HEAs was discussed, and the oxidation mechanism was summarized. The results indicate that, at 800 °C, the AlTiNiCuCox (x = 0.5, 1.0, 1.5) series HEAs had dense oxide films and certain high-temperature oxidation resistance. With increasing Co content, the high-temperature oxidation resistance of the alloys also increased. With increasing time at high temperature, there was a significant increase in the contents of oxide species and Ti on the oxide film surface. In the process of high-temperature oxidation of AlTiNiCuCox series HEAs, the interfacial reaction, in which metal elements and oxygen in the alloy form ions through direct contact reaction, initially dominated, then the diffusion process gradually became the dominant oxidation factor as ions diffused and were transported in the oxide film.

Effect of High Temperature on Wear Behavior of Stir Cast Aluminium/Boron Carbide Composites

2020 ◽  
Vol 22 (4) ◽  
pp. 1031-1046
Author(s):  
X. Canute ◽  
M. C. Majumder
Keyword(s):  
High Temperature ◽  
Wear Rate ◽  
Boron Carbide ◽  
Wear Behavior ◽  
Base Alloy ◽  
Weight Fraction ◽  
Sliding Velocity ◽  
Wear Properties ◽  
High Temperature Wear ◽  
The Matrix

AbstractThe need for development of high temperature wear resistant composite materials with superior mechanical properties and tribological properties is increasing significantly. The high temperature wear properties of aluminium boron carbide composites was evaluated in this investigation. The effect of load, sliding velocity, temperature and reinforcement percentage on wear rate was determined by the pin heating method using pin heating arrangement. The size and structure of base alloy particles change considerably with an increase of boron carbide particles. The wettability and interface bonding between the matrix and reinforcement enhanced by the addition of potassium flurotitanate. ANOVA technique was used to study the effect of input parameters on wear rate. The investigation reveals that the load had higher significance than sliding velocity, temperature and weight fraction. The pin surface was studied with a high-resolution scanning electron microscope. Regression analysis revealed an extensive association between control parameters and response. The developed composites can be used in the production of automobile parts requiring high wear, frictional and thermal resistance.

Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Die Casting ◽  
Casting Machine ◽  
Injection Pressure ◽  
Casting Process ◽  
Matrix Alloy ◽  
Content Type ◽  
The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

Comparative studies of nitrogen plasma and argon plasma treatment on the strength of PBO fibre reinforced high-temperature resistant thermoplastic composite

2021 ◽  
pp. 095400832098729
Author(s):  
K Sudheendra ◽  
Jennifer Vinodhini ◽  
M Govindaraju ◽  
Shantanu Bhowmik
Keyword(s):  
Contact Angle ◽  
High Temperature ◽  
Plasma Treatment ◽  
Sessile Drop ◽  
Dynamic Contact Angle ◽  
Argon Plasma ◽  
Film Surface ◽  
Fibre Surface ◽  
Nitrogen Plasma ◽  
Thermoplastic Composite

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

Oxidation Effects during High Temperature Deformation of CP Ti Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3678-3683
Author(s):  
Ming Jen Tan ◽  
X.J. Zhu ◽  
S. Thiruvarudchelvan ◽  
K.M. Liew
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
High Temperatures ◽  
Pure Titanium ◽  
Initial Strain Rate ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Commercially Pure Titanium ◽  
Commercially Pure

This work reports the influence of oxidation on the superplasticity of commercially pure titanium at high temperatures. Uniaxial tensile tests were conducted at temperatures in the range 600-800°C with an initial strain rate of 10s-1 to 10s-3. This study shows that oxidization at the surface of the alloy causes oxide film on the surface of commercially pure titanium alloy, and the thickness of oxide film increase with increasing exposure time and temperature. XRD analysis shows that the oxide film consists of TiO2. Because this oxide film is very brittle, it can induce clefts and degrade the ductility of the titanium at high temperatures. The mechanism of the initial clefts was investigated and a model for the cleft initiation and propagation during high temperature tensile test was proposed.

Effect of recess depth on lubrication performance of annular recess hydrostatic thrust bearing by constant rate flow

2018 ◽  
Vol 70 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jun-peng Shao ◽  
Guang-dong Liu ◽  
Xiao-dong Yu ◽  
Yan-qin Zhang ◽  
Xiu-li Meng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Simulation Method ◽  
Content Type ◽  
Oil Film ◽  
Constant Rate ◽  
Lubrication Performance ◽  
Optimal Value ◽  
Improved Performance ◽  
Lubrication Characteristics ◽  
Volume Method

Purpose The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow. Design/methodology/approach The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method. Findings The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing. Originality/value The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

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