scholarly journals Influence of pulsed plasma treatment on phase composition and hardness of Cr3C2-NiCr coatings

2021 ◽  
Vol 5 (1) ◽  
pp. 45-51
Author(s):  
D.N. Kakimzhanov ◽  
B.K. Rakhadilov ◽  
Yu.N. Tyurin ◽  
O.V. Kolisnichenko ◽  
L.G. Zhurerova ◽  
...  
Keyword(s):  
Phase Composition ◽  
Plasma Treatment ◽  
Physical And Mechanical Properties ◽  
Oxide Phase ◽  
Mechanical Tests ◽  
Pulse Plasma ◽  
Pulsed Plasma ◽  
X Ray Diffraction ◽  
Detonation Spraying ◽  
Carbide Particles

In this study, the research results of the influence of pulsed plasma treatment on phase composition, hardness, and roughness of Cr3C2-NiCr coatings are presented. The Cr3C2-NiCr coating was applied to substrate 12Kh18N10T stainless steel by detonation spraying method. To change the physical and mechanical properties of sprayed coating’s surface layers, subsequent pulse-plasma treatment was used. The pulse-plasma treatment leads to changing the roughness of Cr3C2-NiCr coating. The results of mechanical tests showed that after pulsed plasma treatment, the hardness of Cr3C2-NiCr coating is increased. Based on X-ray diffraction analysis, it was found that the hardness increasing of coating is associated with phase transformations on the surface layer, in particular, the formation of the oxide phase and an increase in the number of carbide particles.

Influence of pulse plasma treatment on the phase composition and microhardness of detonation coatings based on Ti-Si-C

2021 ◽  
Vol 102 (2) ◽  
pp. 33-39
Author(s):  
B.K. Rakhadilov ◽  
◽  
D.B. Buitkenov ◽  
M. Adilkhanova ◽  
Zh.B. Sagdoldina ◽  
...  
Keyword(s):  
Phase Composition ◽  
Plasma Treatment ◽  
Solid Phase ◽  
High Hardness ◽  
Pulse Plasma ◽  
Pulsed Plasma ◽  
Study Results ◽  
Plasma Effects ◽  
High Microhardness ◽  
Mode 3

The paper considers the study results of the phase composition and microhardness of detonation coatings based on Ti-Si-C after exposure to pulsed plasma treatment. The CCDS2000 detonation complex was used to obtain the coatings. Coatings surface modification was carried out using pulsed plasma exposure (PPE). The detonation coatings were treated with varying the distance H (30 mm mode 1, 40 mm mode 2, 50 mm mode 3) from the plasmatron to the hardened surface. It is shown that the treated coatings are generally characterized by high microhardness compared to the original coating. It was determined that after treatment by pulsed plasma effects an increase in the intensity of all reflexes phase Ti3SiC2 was observed, and the appearance of reflexes (101, 102, 112, 204, 0016) phase Ti3SiC2 was found, which indicates the increase of the content of Ti3SiC2 phase. The change in the fraction of phases indicates a solid-phase transformation during pulsed-plasma activation. High hardness is observed on the coating surface treated according to mode 3 (50 mm) and as it approaches the surface of the substrate modes 2 (40 mm) and 1 (30 mm) the hardness decreases. It is established that the increase in the microhardness of detonation coatings after pulse-plasma treatment is associated with an increase in the content of Ti3SiC2 phases in the coatings, as well as an increase in the defects density in the modified layer.

scholarly journals The influence of pulse-plasma treatment on the phase composition and hardness of Fe-TiB2-CrB2 coatings

2021 ◽  
Vol 5 (2) ◽  
pp. 155-162
Author(s):  
A.B. Kengesbekov ◽  
B.K. Rakhadilov ◽  
Yu.N. Tyurin ◽  
N.M. Magazov ◽  
M.K. Kylyshkanov ◽  
...  
Keyword(s):  
Phase Composition ◽  
Plasma Treatment ◽  
Pulse Plasma ◽  
Surface Layers ◽  
X Ray ◽  
Oxide Phases ◽  
Detonation Method ◽  
Sprayed Coating ◽  
Carbide Particles ◽  
Coating Hardness

This work are presented the research results of pulse plasma treatment influence on the phase composition, hardness, roughness and element composition of coatings on the bases of Fe-TiB2-CrB2. The Fe-TiB2-CrB2 coating was deposited by detonation method. The following pulse-plasma treatment was used to modify the structure and properties of the surface layers of the sprayed coating. The results of mechanical experiments showed that the hardness of Fe-TiB2-CrB2 coating increased after the treatment. On the basis of the X-ray analysis, it has been established that the increase of coating hardness is connected with phase transformations in a surface layer, in particular, with formation of oxide phases and increase of carbide particles quantity.

Study of the Potentiality of Residue from Kaolin Industry as Ceramic Raw Material to Produce Porcelanate Gres

2005 ◽  
Vol 498-499 ◽  
pp. 420-424
Author(s):  
M.A.F. Ramalho ◽  
Lisiane Navarro de Lima Santana ◽  
Gelmires Araújo Neves ◽  
Hélio Lucena Lira
Keyword(s):  
Public Health ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Public ◽  
The World ◽  
The Impact ◽  
Scanning Electron

The recycling of industrial residues has being intensified all over the world, mainly due to the increase of the impact to the environment, and the growing volume of solid residues that put in risk the public health and degrade the natural resources. So, the aim of this work is to study the potentiality of the residue from kaolin industry, as ceramic raw material to produce porcelanate gres. A composition was formulated, mixed and forming by pressing (from 30 MPa to 50 MPa). After, it was sinterized at temperatures of 1180°C, 1200°C, 1220°C and 1240°C. The samples were submitted to physical and mechanical tests and characterized by X-ray diffraction and scanning electron microscopy. The preliminary results from physical and mechanical properties showed that the residue can be used to produce porcelanate gres according to Brasilian Norms (NBR 13818), at temperatures of 1220°C and 1240°C.

scholarly journals Influence of Detonation-Spraying Parameters on the Phase Composition and Tribological Properties of Al2O3 Coatings

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 793
Author(s):  
Nurgamit Kantay ◽  
Bauyrzhan Rakhadilov ◽  
Sherzod Kurbanbekov ◽  
Didar Yeskermessov ◽  
Gulnara Yerbolatova ◽  
...  
Keyword(s):  
Phase Composition ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
Detonation Spraying ◽  
Spraying Parameters ◽  
Detonation Method ◽  
Al2o3 Phase ◽  
Detonation Gun ◽  
Α Al2o3 ◽  
Degree Of Filling

Al2O3 coatings were applied on the surface of 12Ch18N10T steel by the detonation method at different degrees of filling of the detonation gun. The aim was to study the influence of technological parameters on the formation of the coating’s structure, phase composition and tribological characteristics. The degree of filling the gun with a gas mixture (C2H2/O2) varied from 53% to 68%. X-ray diffraction study showed that the content of α-Al2O3 increases depending on the degree of filling. The results showed that the hardness increases with an increase in the α-Al2O3 phase. When the gun is 53% filled with gas, the Al2O3-based coating has the hardness of 20.56 GPa compared to 58%, 63% and 68% fillings. Tribology tests have shown that the wear rate and friction coefficient of the coating is highly dependent on the degree of filling of the gun.

scholarly journals Effect of Pulsed-Plasma Treatment on the Structural-Phase Composition and Tribological Properties of Detonation Coatings Based on Ti–Si–C

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 795
Author(s):  
Bauyrzhan Rakhadilov ◽  
Dastan Buitkenov ◽  
Zhanat Idrisheva ◽  
Manira Zhamanbayeva ◽  
Sapargali Pazylbek ◽  
...  
Keyword(s):  
Surface Layer ◽  
Plasma Treatment ◽  
Tribological Properties ◽  
Structural Phase ◽  
Xrd Analysis ◽  
Pulsed Plasma ◽  
Detonation Spraying ◽  
Before And After ◽  
Oxide Phases ◽  
Set Up

The structural-phase state and tribological characteristics of detonation coatings based on Ti–Si–C before and after pulsed-plasma exposure have been experimentally investigated. The authors of the research used a detonation set-up of CCDS2000 to obtain coatings. The modification of coating surfaces was carried out by a pulsed-plasma flow using the “Impulse-6” installation. The results of the research have shown that the modification of coatings surface by a pulsed-plasma effect causes an increase in the microhardness of the surface layer and in its wear resistance. It was determined that after such type of treatment, there is an increase in the content of the Ti3SiC2 phase. According to the results of XRD analysis, the improvement in the mechano-tribological properties of detonation spraying coatings of the Ti–Si–C system as a result of pulsed-plasma treatment is associated with an increase in the content of Ti3SiC2 phases in the coatings, as well as the formation of carbide and oxide phases on the surface layer.

scholarly journals DETERMINATION OF THE CAUSES OF DESTRUCTION OF HIGH-STRENGTH FASTENING ELEMENTS

2021 ◽  
Vol 83 (2) ◽  
pp. 207-219
Author(s):  
O.B. Berdnik ◽  
I.N. Tsareva ◽  
L.A. Krivina ◽  
S.V. Kirikov ◽  
Yu.P. Tarasenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Mechanical Tests ◽  
Modern Technology ◽  
Regulatory Requirements ◽  
Two Phase ◽  
Average Value ◽  
Elastic And Plastic Deformations

Intensively operated modern technology requires the use of high-strength fasteners. The article presents the results of studies of the structure and physical and mechanical properties of the material of fastening elements (threaded hardware) in order to determine the causes of their destruction during operation. The fractographic analysis of fractures of fractured bolts revealed pronounced centers of crack initiation with traces of delayed brittle fracture, which is typical for high-strength hardware that are under high load for a long time, close to the yield point. Mechanical tests of the studied fastening elements showed increased values of ultimate strength. The performed relaxation tests of the material of broken bolts also revealed an increased value of the microplasticity limit, which is responsible for the onset of plastic deformation processes in microvolumes of the material, and for the material of whole hardware, the value of the limit is included in the permissible interval. At the same time, the average hardness of the material of all products meets the regulatory requirements. The maximum spread of hardness 70 HB is fixed on the destroyed bolt. Using the experimental values of microhardness, theoretical estimates of the coefficient of plasticity, which characterize the ability of a material to perceive elastic and plastic deformations, were carried out. To ensure a sufficient level of ductility of a long-term working metal material, the ductility coefficient must be at least 0.8. The average value of the hardness of the material of the fastening elements satisfies this criterion for assessing ductility. According to the results of a step-by-step analysis of the microstructure of the samples, the inhomogeneity of the distribution of the carbide phase over the cross-section of the bolts was established. The two-phase composition (a-Fe + Fe3C) of steel was established by X-ray structural analysis, which confirms the results of microstructural studies. It should be noted that the phase composition of all studied samples is identical. Based on the results of the studies carried out, it was found that the destruction occurred due to the reduced strength and increased fragility of the material due to the presence of microdefects. The material of the whole bolts in terms of structure and mechanical properties comply with regulatory requirements.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Formation of nanoscale sodium dodecahydro-closo- dodecaborate Na2[B12H12] on silicate matrix surface

2019 ◽  
Vol 484 (1) ◽  
pp. 41-43
Author(s):  
E. A. Malinina ◽  
V. K. Skachkova ◽  
I. V. Kozerozhets ◽  
V. V. Avdeeva ◽  
L. V. Goeva ◽  
...  
Keyword(s):  
Phase Composition ◽  
Ammonium Salt ◽  
Liquid Glass ◽  
Silicate Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Salt Sample ◽  
Matrix Surface

The method of nanoscaled sodium dodecahydro-closo-dodecaborate Na2[B12H12] synthesis is presented. The composite is heated to 200°C to yield the desired product, forming with the introduction of triethyl- ammonium salt [Et3NH]2[B12H12] into the silicate matrix of a sodium liquid glass. The morphology and phase composition of the synthesized sample are studied through SEM and X-ray diffraction methods, in comparison to those of a standard salt sample Na2[B12H12]. Based on the obtained data, the sample under study is an amorphous composite, on the surface of which nanoscale crystals of Na2[B12H12] form.

scholarly journals Characterization of Beeswax, Candelilla Wax and Paraffin Wax for Coating Cheeses

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Adolfo Bucio ◽  
Rosario Moreno-Tovar ◽  
Lauro Bucio ◽  
Jessica Espinosa-Dávila ◽  
Francisco Anguebes-Franceschi
Keyword(s):  
Physical And Mechanical Properties ◽  
Tensile Tests ◽  
Paraffin Wax ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Dimensional Changes ◽  
Ductile Behavior ◽  
Candelilla Wax

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.

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