INFLUENCE OF ELECTROLYTIC-PLASMA SURFACE HARDENING ON THE SURFACE PROPERTIES OF BANDAGE STEEL

Tribologia ◽  
2019 ◽  
Vol 286 (4) ◽  
pp. 105-111
Author(s):  
Erkezhan TABIEVA ◽  
Bauyrzhan RAHADILOV ◽  
Zarina SATBAEVA ◽  
Aidar KENESBEKOV ◽  
Gulzhaz UAZYRKHANOVA

This work is devoted to the research of the influence of the technological parameters of electrolytic-plasma surface hardening on the structure and tribological properties of the surface of samples of the retaining steel Mark 2. Electrolytic-plasma surface hardening was carried out in an electrolyte from an aqueous solution of 10% urea and 10% sodium carbonate. According to the result of metallographic and X-ray diffraction analysis, it was determined that the phase composition of steel Mark 2 after processing varies, and fine martensite with a small amount of troostite and iron oxide is formed on the surface of the samples. Tribological experiments of samples without lubrication were carried out. These experiments have shown that all the samples studied have an increased wear resistance, which may be associated with the formation of a fine-grained martensitic structure. It was shown that from the point of view of the complex of the properties obtained, and the most promising is electrolytic-plasma action with a treatment time of 4 s.

2020 ◽  
Vol 989 ◽  
pp. 787-792
Author(s):  
Erkezhan Erkinbekkyzy Tabieva ◽  
Laila Gylymmeddenovna Zhurerova ◽  
Daryn Baizhan

This work is devoted to the study of the influence of technological parameters of electrolytic-plasma surface quenching (EPQ) on the structure and surface properties of samples of bandage steel 2. In the electrolytic-plasma treatment, we performed the cathode mode in an electrolyte containing an aqueous solution of 20% carbamide (NH2)2CO and 20% sodium carbonate Na2CO3, on the installation of EPO with appropriate technological processing conditions. According to the electron-optical, X-ray phase studies, the phase composition of the steel after the EPQ was determined. This differs from the initial one by the formation of cementite and iron oxides on the surface of the samples. It is established that the microhardness of the bandage steel 2 after the EPQ during heating for 4 seconds increases 2.4 times, in comparison with the initial state.


2020 ◽  
Vol 839 ◽  
pp. 57-62
Author(s):  
Erkezhan Erkinbekkyzy Tabieva ◽  
Laila Gylymmeddenovna Zhurerova ◽  
Daryn Baizhan

This work is devoted to the study of the influence of technological parameters of electrolytic-plasma surface quenching (EPQ) on the structure and surface properties of samples of bandage steel 2. In the electrolytic-plasma treatment, we performed the cathode mode in an electrolyte containing an aqueous solution of 20% carbamide (NH2)2CO and 20% sodium carbonate Na2CO3, on the installation of EPO with appropriate technological processing conditions. According to the electron-optical, X-ray phase studies, the phase composition of the steel after the EPQ was determined this differs from the initial one by the formation of cementite and iron oxides on the surface of the samples. It is established that the microhardness of the bandage steel 2 after the EPQ during heating for 4 seconds increases 2.4 times in comparison with the initial state.


Carburizing technique has recently been developed to engineer the surfaces of the low steels for combined improvement in wear and fatigue resistance. The resultant carburized surface region is characterized by the high saturation of carbon in austenite lattices of steel. The duration and temperature of carburising surface hardening treatment can be chosen in agreement with the thermal treatment for obtaining optimal bulk hardness in the precipitation hardening steel. Characterization point of view structural and mechanical of the samples using X-ray diffraction, optical microscopy and micro indentation testing was then introduced in this work. It was found that the incorporation of carbon resulted in a hardened additional compounds consisting of a combination of martensite and expanded austenite.


2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.


1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 570
Author(s):  
Olga Sánchez ◽  
Manuel Hernández-Vélez

ZnOTe compounds were grown by DC magnetron cosputtering from pure Tellurium (Te) and Zinc (Zn) cathodes in O2/Ar atmosphere. The applied power on the Zn target was constant equal to 100 W, while the one applied on the Te target took two values, i.e., 5 W and 10 W. Thus, two sample series were obtained in which the variable parameter was the distance from the Te targets to the substrate. Sample compositions were determined by Rutherford Backscattering Spectroscopy (RBS) experiments. Structural analysis was done using X-Ray diffraction (XRD) spectrometry and the growth of the hexagonal w-ZnO phase was identified in the XRD spectra. RBS results showed high bulk homogeneity of the samples forming ZnOTe alloys, with variable Te molar fraction (MF) ranging from 0.48–0.6% and from 1.9–3.1% for the sample series obtained at 5 W and 10 W, respectively. The results reflect great differences between the two sample series, particularly from the structural and optical point of view. These experiments point to the possibility of Te doping ZnO with the permanence of intrinsic defects, as well as the possibility of the formation of other Te solid phases when its content increases. The results and appreciable variations in the band gap transitions were detected from Photoluminescence (PL) measurements.


Author(s):  
Ke Guo ◽  
Shaoyan Wang ◽  
Renfeng Song ◽  
Zhiqiang Zhang

AbstractLeaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.


2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.


2020 ◽  
pp. 554-559
Author(s):  
V.E. Arkhipov ◽  
T.I. Murav’eva ◽  
M.S. Pugachev ◽  
I.V. Shkaley

The results of effect of deposition temperature and the overlap coefficient on the formation of the phase composition of coating based on Cu, Zn and Al2O3 particles mixture applied by cold gas-dynamic deposition are presented. Using X-ray diffraction and X-ray spectral analysis, it is shown that when using the 55 % overlap coefficient electron-type compound based on CuZn3 (ε-phase) is formed in the coating, the mass fraction of which increases to 11.4 % with increase in the deposition temperature. Deposition with 64 % overlap coefficient is accompanied by the formation not only of the ε-phase, but of electron-type compound based on Cu5Zn8 (γ-phase), the mass fraction of which increases to 33 % at temperature of 450 °C. In the process of coating deposition, the predominant diffusion copper into zinc takes place; the calculations show high value of the diffusion coefficient copper — 1,56•10–13 m2 /s.


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