SYNTHESIS OF ANTIFRICTION COATINGS BY THE FABO METHOD

2021 ◽  
Vol 1 (142) ◽  
pp. 140-147
Author(s):  
Aleksey G. Ipatov ◽  
◽  
Sergey N. Shmykov

In the paper, the technology of obtaining antifriction coatings by the method of finishing antifriction-free abrasive treatment with the implementation of the wear-free effect is proposed. (Research purpose) The research purpose is in developing an effective technology for obtaining copper coatings on the surface of steel parts of the shaft type to reduce the wear rate in the conditions of oil starvation of machine parts. (Materials and methods) During the study, a laboratory facility for the synthesis of antifriction coatings on the surface of steel parts by the method of finishing antifriction-free abrasive treatment has been developed. Brass of the LS-59-1 brand was used as a material for applying a copper antifriction coating. In order to activate the surface of the part and the surface of the filler material, a technological medium based on a ten percent solution of hydrochloric acid and glycerol was used. Authors determined the composition of the technological environment empirically. The obtained laboratory samples were subjected to tribological studies in comparison with standard antifriction alloys. X-ray diffraction studies were performed to determine the phase composition. (Results and discussion) As a result of X-ray diffraction studies of laboratory samples, the presence of iron and copper components in the synthesized coating was studied. The content of oxides on the surface of the coating is insignificant, the internal structure is dense with no visible porosity. The coating consists of 95 percent copper, the synthesis process takes place without oxidation, which gives the coating a high adhesive and cohesive strength. The coating thickness is uniform and varies within 3-5 micrometers. (Conclusions) Comparative tribological studies have shown high resistance to wear and to the setting of the contact surfaces under conditions of oil starvation. The coefficient of friction is stable and low and is in the range of 0.08-0.15. The developed technology makes it possible to increase the wear resistance of steel parts of the shaft type in the shortest possible time and with minimal material costs and can be successfully implemented in the conditions of repair enterprises.

2021 ◽  
Vol 1 (142) ◽  
pp. 140-147
Author(s):  
Aleksey Ipatov ◽  
◽  
Sergey Shmykov

In the paper, the technology of obtaining antifriction coatings by the method of finishing antifriction-free abrasive treatment with the implementation of the wear-free effect is proposed. (Research purpose) The research purpose is in developing an effective technology for obtaining copper coatings on the surface of steel parts of the shaft type to reduce the wear rate in the conditions of oil starvation of machine parts. (Materials and methods) During the study, a laboratory facility for the synthesis of antifriction coatings on the surface of steel parts by the method of finishing antifriction-free abrasive treatment has been developed. Brass of the LS-59-1 brand was used as a material for applying a copper antifriction coating. In order to activate the surface of the part and the surface of the filler material, a technological medium based on a ten percent solution of hydrochloric acid and glycerol was used. Authors determined the composition of the technological environment empirically. The obtained laboratory samples were subjected to tribological studies in comparison with standard antifriction alloys. X-ray diffraction studies were performed to determine the phase composition. (Results and discussion) As a result of X-ray diffraction studies of laboratory samples, the presence of iron and copper components in the synthesized coating was studied. The content of oxides on the surface of the coating is insignificant, the internal structure is dense with no visible porosity. The coating consists of 95 percent copper, the synthesis process takes place without oxidation, which gives the coating a high adhesive and cohesive strength. The coating thickness is uniform and varies within 3-5 micrometers. (Conclusions) Comparative tribological studies have shown high resistance to wear and to the setting of the contact surfaces under conditions of oil starvation. The coefficient of friction is stable and low and is in the range of 0.08-0.15. The developed technology makes it possible to increase the wear resistance of steel parts of the shaft type in the shortest possible time and with minimal material costs and can be successfully implemented in the conditions of repair enterprises.


Author(s):  
Aleksey G. Ipatov ◽  
Sergey N. Shmykov

This paper proposes the technology for obtaining antifriction coatings by short-pulse laser treatment of powder compositions. (Research purpose) The research purpose is in synthesizing thin anti-friction coatings on the surface of steel substrates by short-pulse laser treatment of metal powder compositions and analyze their physical and mechanical properties. (Materials and methods) A solid-state pulsed laser generator was used to synthesize antifriction coatings. B83 babbit powder has been used as an additive material. The powder composition was additionally doped with PMS-1 copper and molybdenum disulfide in order to increase the friction properties and load-bearing capacity of the coatings. Laboratory samples were subjected to wear tests under boundary friction conditions using the SMT-2070 friction machine in comparison with standard surfaces of B83 babbite coating, steel surface, and Molykote d-321R clad surface. X-ray diffractometer DRON-6 was used for x-ray diffractometry. (Results and discussion) It was found that the porosity of the modified coating does not exceed 5 percent, and there are no traces of detachment and destruction in the experimental samples. It was found that the coefficient of friction of the analyzed coating under conditions of boundary friction was 0.12-0.13, which corresponds to the coefficient of friction of a standard babbit alloy. The modified coating have a more efficient workability and a stable coefficient of friction over a large range of loads. It was found that the wear intensity of the analyzed coating is significantly lower than one of the compared surfaces. The increase in friction characteristics is due to the features of the coating structure, which is characterized by a large number of solid intermetallic compounds Cu3Sn having a hexagonal structure, which determines the low friction coefficient. (Conclusions) The results shows the high practical potential of modified antifriction coatings that can be used in mechanical engineering and repair production in the design and restoration of bearing assemblies.


2014 ◽  
Vol 941-944 ◽  
pp. 280-283
Author(s):  
Xiao Yang Wang ◽  
Hong Qiang Ru

SiC particle-reinforced Cu-Fe based braking materials were fabricated by the P/M hot pressing method. The phase composition, microstructure and the worn surface of the composite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD).The tribological properties were evaluated using a disk-on-disk type laboratory scale dynamometer. Results indicate that the friction coefficient is 0.42 in 6800rpm, 0.7MPa. With the increase of rotation speeds the coefficient of friction and stable rate were decreased.


Author(s):  
Mahendran Samykano ◽  
Ram Mohan ◽  
Shyam Aravamudhan

This paper presents results and discussion from a comprehensive morphological and crystallographic characterization of nickel nanowires synthesized by template-based electrodeposition method. In particular, the influence of magnetic and electric field (current density) conditions during the synthesis of nickel nanowires was studied. The structure and morphology of the synthesized nanowires were studied using Helium ion microscopy (HIM) and scanning electron microscopy (SEM) methods. The HIM provided higher quality data and resolution compared to conventional SEM imaging. The crystallographic properties of the grown nanowires were also studied using X-ray diffraction (XRD). The results clearly indicated that the morphological and crystallographic properties of synthesized nickel nanowires were strongly influenced by the applied magnetic field and current density intensity during the synthesis process.


2019 ◽  
Vol 57 (3A) ◽  
pp. 21
Author(s):  
Minh Truong Xuan Nguyen ◽  
Thu Thi Minh Bui ◽  
Cuc Thi Le ◽  
Linh Huu Nguyen ◽  
Y Ngoc Pham ◽  
...  

Nickel nanostructures prepared by various methods have received considerable attentions due to their numerous applications. In this study, one-dimensional nickel nanowires (NiNWs) were synthesized by the reduction of nickel (II) chloride in polyol medium. Poly (vinylpyrrolidone) (PVP) served as the surfactant and hydrazine hydrate was used as the reductant. The effects of different experimental parameters, i.e. concentration of Ni2+, volume of N2H4, concentration of PVP and reaction temperature on the formation and morphology of NiNWs were studied. The structure, composition and surface morphology of the materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the morphology as well as the diameter of NiNWs could be effectively controlled by adjusting parameters of the synthesis process.


2010 ◽  
Vol 177 ◽  
pp. 673-676 ◽  
Author(s):  
Jun Xue ◽  
Hou Kui Xiang ◽  
Hong Qiao Ding ◽  
Shu Li Pang ◽  
Xue Hua Wang ◽  
...  

Carbon encapsulated Fe-Cu alloys nanoparticles were synthesized by using ferric nitrate, copper nitrate as metal sources and using sucrose as carbon source. The synthesis process involved a step of hydrazine hydrate reduction in alcohol solution and a step of annealing carbonization. The as-prepared samples were characterized by X-ray diffraction technique, X-ray energy dispersion spectrograph, trans- mission electron microscopy and Raman spectroscopy. The results showed the sample was core / shell structure, the metalic core was crystalline FeCu4 alloy, the shell was amorphous carbon, and the average particle size was about 51nm. The magnetic measurement by using a vibrating sample magnetometer revealed that the sample has ultra-soft magnetic property with the saturation magnetization Ms of 13.01 emu/g, residual magnetization Mr of 0.37 emu/g and coercive forces Hc of 54.43 Oe at room temperature.


Author(s):  
Tarun Goyal ◽  
T. S. Sidhu ◽  
R. S. Walia

This study reveals the successful low pressure cold spray deposition of near-uniform, defect free and dense copper coatings approximately 700-1900 µm thick, on Al alloy for electro-technical applications. The micro structural characteristics of the deposits have been studied using the combined techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electron-probe micro analysis (EPMA). The coatings exhibited characteristic splat-like, layered morphologies due to the deposition of solid powder particles which appeared to have been plastically deformed on impact to the substrate. The developed coatings have a dense (in the range of 3090-5015 kg/m3)and nearly uniform microstructure, with almost uniform hardness values in the range of 120 -140 Hv, and electrical conductivity in the range of 23-30 MS/m. EDAX, XRD and EPMA results revealed that the main constituent in the coating is Cu.


NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.


2011 ◽  
Vol 306-307 ◽  
pp. 429-432
Author(s):  
Hui Han ◽  
Hua Ming Miao ◽  
Sheng Fa Liu ◽  
Yang Chen

Experiments were conducted to fabricate the Al4C3 particles by powder in-situ synthesis process under argon atmosphere and examine the grain refinement of AZ91D magnesium alloy with the addition of 0.6%Al4C3(hereafter in mass fraction,%). By means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), the results show the successful fabrication of Al4C3 particles. After adding 0.6%Al4C3, the average grain size of AZ91D magnesium alloy decreased from 360μm to 243μm. Based on the differential thermal analysis (DTA) results and calculations of the planar disregistry between Al4C3 and α-Mg, Al4C3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Yongbiao Wan ◽  
Sihong Wang ◽  
Wenhao Luo ◽  
Lianhua Zhao

Adjusting pH with an ammonia solution during the synthesis, single-crystalline BiVO4has been prepared using Bi(NO3)3·5H2O and NH4VO3as starting materials through aqueous-phase precipitation at room temperature. The prepared samples are characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). The impact of pH on structure, surface morphology, visible-light photocatalytic activity, and light absorption performance of BiVO4is explored and discussed. During the synthesis process, neither extremely acidic (low pH) nor basic (high pH) conditions are desirable for the formation of BiVO4in monoclinic phase. The highest photocatalytic performance on the degradation of a methylene blue solution is observed under pH=7.0for BiVO4in monoclinic scheelite, which is attributed to its small grain size and marked surface oxygen evolution ability.


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