scholarly journals MICROSTRUCTURE AND WEAR PROPERTIES OF COATINGS ON VALVE STEEL PRODUCED BY TRD METHOD

2016 ◽  
Vol 11 (3) ◽  
pp. 75-85
Author(s):  
Serkan Islak ◽  
Cihan Özorak ◽  
Cihangir Tevfik Sezgin ◽  
Mehmet Akkaş
Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 346
Author(s):  
Rouhollah Mousavi ◽  
Flavio Deflorian ◽  
Mohammad Ebrahim Bahrololoom

Ni–Mo/Al composite coatings were obtained by electrodeposition from a Ni–Mo plating bath containing suspended Al particles. The factors including temperature, current density, and stirring rate affecting coating composition, wear, roughness, and morphology have been studied. It was found that properties such as hardness, roughness, wear, and the Al particle content showed parabolic behavior when changing each parameter. That means that there is a critical value for the mentioned parameters at which the properties of coatings become maximal.


2019 ◽  
Vol 125 ◽  
pp. 299-313 ◽  
Author(s):  
Fuqiang Lai ◽  
Shengguan Qu ◽  
Roger Lewis ◽  
Tom Slatter ◽  
Wenlan Fu ◽  
...  

2019 ◽  
Vol 822 ◽  
pp. 709-715
Author(s):  
Boris Aleksandrovich Shemyakinskiy ◽  
Margarita Alexandrovna Skotnikova ◽  
Zi Xi Wang ◽  
Aleksey Aleksandrovich Alkhimenko

The paper presents the results of tribotechnical studies of anti-wear properties of iron-based coatings for light-alloy drill pipes made of aluminum alloys. The description of the tribotechnical stand simulating real processes of drilling in a wide range of conditions is given. Also, the analysis of corrosion resistance of coatings by electrochemical analysis was carried out. The results showed that there is a potential for the use of this type of coating.


1999 ◽  
Vol 122 (3) ◽  
pp. 646-649 ◽  
Author(s):  
Binshi Xu ◽  
Wei Zhang ◽  
Shining Ma ◽  
Baohong Tian ◽  
Xiubing Liang

The microstructure of spray coatings using a newly developed thermal spray technique, High Velocity Arc Spray (HVAS), was studied and compared with those of regular arc sprayed coatings. The mechanical and wear properties of HVAS coatings were also investigated. The test results showed that HVAS coatings had better mechanical properties than those of regular arc sprayed coatings. The bonding strength of HVAS Al and 3Cr13 coatings was increased by 114 percent and 51.8 percent; the relative wear resistance of HVAS coatings was about twice that of regular arc sprayed coatings. The difference of microstructure and tribological properties between HVAS and regular arc sprayed coatings was discussed. [S0742-4787(00)00203-4]


2021 ◽  
Author(s):  
Huu Chien NGUYEN ◽  
Emil SVOBODA ◽  
Jiří PROCHAZKA ◽  
Tomáš DRAŽAN ◽  
Horníček JAKUB ◽  
...  

2012 ◽  
Vol 482-484 ◽  
pp. 2371-2375
Author(s):  
Xiao He Wang ◽  
Bin Shi Xu ◽  
Zhen Feng Hu ◽  
Shi Yun Dong

To remanufacture hard chromium-plated workpiece, nano-Al2O3/Ni-Co composite coatings and Ni-Co alloy coatings are developed using electric brush plating technology. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) are used to analyze the surface morphology, phase structure and wear properties of coatings. The surface morphology of nano-composite coating is more compact. The nano-particles are well-distributed in the coating and bounded tightly with the substrate. The hardness of composite coating is HV1027, increased approximately 38% compared with Ni-Co alloy coating, overtaking the hard chrome plating. The results of sliding wear test shows that the nano-composite coating reduces friction coefficient, increases wear resistance significantly and exceeds the chromium plating.


Author(s):  
H. Sh. Hammood ◽  
S. S. Irhayyim ◽  
A. Y. Awad ◽  
H. A. Abdulhadi

Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical and wear properties, such as micro-hardness, dry sliding wear, density, and porosity were studied in detail. The wear tests were carried out at a fixed time of 20 minutes while the applied loads were varied (5, 10, 15, and 20 N). SEM images revealed that CNTs were uniformly distributed with relative agglomeration within the Cu/Fe matrix. The results showed that the hardness, density, and wear rates decreased while the percentage of porosity increased with increasing the CNT volume fraction. Furthermore, the wear rate for all the CNTs contents increased with the applied load.


Author(s):  
Gibin Gil ◽  
Sujin Lee

ABSTRACT In radial tires, belt structure plays a role of minimizing the lateral deflection of carcass, which has a significant influence on the cornering and wear properties of a tire. The deflection of carcass affects the magnitude of tread block deformation when the tire is under the slip angle. As a result, it can change the cornering stiffness characteristics of the tire, especially when the vertical load is high. During tire development, a tire design engineer tries to find the optimal belt ply angle that satisfies the various performance requirements simultaneously, but it is not an easy task because the effect of belt angle change is different depending on the size of the tire. There have been many attempts to construct a mathematical model that represents the structural properties of the belt package, including the string-based model and the beam on elastic foundation model. But, in many cases, only the in-plane bending of belt is considered and the shear deformation is not taken into consideration. In this study, the effect of belt angle change on belt stiffness is analyzed using a mathematical model based on the Timoshenko beam theory. This model can account for the in-plane bending and shear deformation of the belt structure at the same time. The results of the analysis show how the contribution of bending and shear is changed depending on a tire design parameter, herein the belt cord angle. The effect of belt ply angle change on cornering stiffness is investigated by means of the brush model including belt flexibility. The prediction by the brush model is compared with the measurement using a Flat-trac machine, and the validity of the model is discussed.


2020 ◽  
Vol 22 (4) ◽  
pp. 1031-1046
Author(s):  
X. Canute ◽  
M. C. Majumder

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.


2020 ◽  
Vol 86 (7) ◽  
pp. 39-44
Author(s):  
K. V. Gogolinsky ◽  
A. E. Ivkin ◽  
V. V. Alekhnovich ◽  
A. Yu. Vasiliev ◽  
A. E. Tyurnina ◽  
...  

Thickness is one of the key indicators characterizing the quality and functional properties of coatings. Various indirect methods (electromagnetic, radiation, optical) most often used in practice to measure thickness are based on the functional dependence of a particular physical parameter of the system «base – coating» on the coating thickness. The sensitivity of these procedures to the certain properties of coatings imposes the main restriction to the accuracy of measurements. Therefore, the development and implementation of the approaches based on direct measurements of geometric parameters of the coating appears expedient. These methods often belong to the class of «destructive» and, in addition to measuring instruments, require the use of special equipment. To ensure the uniformity of measurements in the laboratory or technological control, these methods are isolated as a separate procedure (method) and must undergo metrological certification in accordance with GOST R 8.563–2009. We present implementation, metrological certification and practical application of the method for measuring thickness of coatings by crater-grinding method. The principles of technical implementation of test equipment, measurement procedure and calculation formulas are described. The results of evaluating the accuracy indicators of the proposed procedure by calculation and experimental methods are presented. In both cases, the relative error did not exceed 6%. The applicability of the developed technique is shown for a wide range of coating materials (from soft metals to superhard ceramics) of different thickness (with from units to hundreds of micrometers). Apart from the goals of process control and outgoing inspection, the method can be recommended as a reference measurement procedure for calibration of measures and adjusting samples for various types of thickness gauges.


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