Peculiarities of the Structure and Phase Composition of Hydroxy Apatite Coatings Sprayed by Laminar Plasma Jet and Treated by Electron Beam

1996 ◽  
Author(s):  
V.A. Klimenov ◽  
Yu. F. Ivanov ◽  
A.V. Karlov ◽  
V.V. Trophimov ◽  
L.B. Bataeva
Keyword(s):  
Electron Beam ◽  
Phase Composition ◽  
Thermal Spraying ◽  
Medical Problem ◽  
Cyclic Strength ◽  
Titanium Implants ◽  
Hydroxy Apatite ◽  
Laminar Plasma Jet ◽  
Scientific Technical ◽  
Titanium Substrates

Abstract The covering of titanium implants by means gas-thermal spraying of hydroxyapatite powders is an actual scientific, technical and medical problem. Application of hydroxyapatite for these purposes is more preferable. However, the problem of its structural and cyclic strength under conditions of bioenvironment response determines of application areas of such coatings and reliability of them usage. Structure and phase composition of hydroxyapatite coating under plasma spraying on titanium substrates and their changing, caused as conditions of forming coating on its increasing, so and conditions of spraying an laminar and turbulent plasma streem were studied. Exact belief about the crystalline structure and phase composition of coating is obtained by methods electronic microscopy and X-ray analysis. Changing of coating structure after sintering in the vacuum and electron beam melting in the vacuum is discussed.

The effect of phase transformations in the process of electrom-beam 3D-printing and post-built heat treatment on the peculiarities of plastic deformation and fracture of high nitrogen Cr-Mn steel

2021 ◽  
pp. 10-17
Author(s):  
E.G. Astafurova ◽  
◽  
K.A. Reunova ◽  
S.V. Astafurov ◽  
M.Yu. Panchenko ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Electron Beam ◽  
Phase Composition ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Raw Material ◽  
High Nitrogen ◽  
Two Phase ◽  
Deformation And Fracture

We investigated the phase composition, plastic deformation and fracture micromechanisms of Fe-(25-26)Cr-(5-12)Mn-0.15C-0.55N (wt. %) high-nitrogen chromium-manganese steel. Obtained by the method of electron-beam 3D-printing (additive manufacturing) and subjected to a heat treatment (at a temperature of 1150°C following by quenching). To establish the effect of the electron-beam 3D-printing process on the phase composition, microstructure and mechanical properties of high-nitrogen steel, a comparison was made with the data for Fe-21Cr-22Mn-0.15C-0.53N austenitic steel (wt. %) obtained by traditional methods (casting and heat treatment) and used as a raw material for additive manufacturing. It was experimentally established that in the specimens obtained by additive manufacturing method, depletion of the steel composition by manganese in the electron-beam 3D-printing and post-built heat treatment contributes to the formation of a macroscopically and microscopically inhomogeneous two-phase structure. In the steel specimens, macroscopic regions of irregular shape with large ferrite grains or a two-phase austenite-ferrite structure (microscopic inhomogeneity) were observed. Despite the change in the concentration of the basic elements (chromium and manganese) in additive manufacturing, a high concentration of interstitial atoms (nitrogen and carbon) remains in steel. This contributes to the macroscopically heterogeneous distribution of interstitial atoms in the specimens - the formation of a supersaturated interstitial solid solution in the austenitic regions due to the low solubility of nitrogen and carbon in the ferrite regions. This inhomogeneous heterophase (ferrite-austenite) structure has high strength properties, good ductility and work hardening, which are close to those of the specimens of the initial high-nitrogen austenitic steel used as the raw material for additive manufacturing.

scholarly journals The Effect of High-Intensity Electron Beam on the Crystal Structure, Phase Composition, and Properties of Al–Si Alloys with Different Silicon Content

2021 ◽  
Vol 22 (1) ◽  
pp. 129-157
Author(s):  
D. V. Zaguliaev ◽  
S. V. Konovalov ◽  
Yu. F. Ivanov ◽  
V. E. Gromov ◽  
V. V. Shlyarov ◽  
...  
Keyword(s):  
Solid Solution ◽  
Electron Beam ◽  
Phase Composition ◽  
Crystal Lattice ◽  
High Intensity ◽  
Materials Science ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Material Surface ◽  
Modified Layer

The study deals with the element–phase composition, microstructure evolution, crystal-lattice parameter, and microdistortions as well as the size of the coherent scattering region in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys irradiated with the high-intensity electron beam. As revealed by the methods of x-ray phase analysis, the principal phases in untreated alloys are the aluminium-based solid solution, silicon, intermetallics, and Fe2Al9Si2 phase. In addition, the Cu9Al4 phase is detected in Al–10.65Si–2.11Cu alloy. Processing alloys with the pulsed electron beam induces the transformation of lattice parameters of Al–10.65Si–2.11Cu (aluminium-based solid solution) and Al–5.39Si–1.33Cu (Al1 and Al2 phases). The reason for the crystal-lattice parameter change in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys is suggested to be the changing concentration of alloying elements in the solid solution of these phases. As established, if a density of electron beam is of 30 and 50 J/cm2, the silicon and intermetallic compounds dissolve in the modified layer. The state-of-the-art methods of the physical materials science made possible to establish the formation of a layer with a nanocrystalline structure of the cell-type crystallization because of the material surface irradiation. The thickness of a modified layer depends on the parameters of the electron-beam treatment and reaches maximum of 90 µm at the energy density of 50 J/cm2. According to the transmission (TEM) and scanning (SEM) electron microscopy data, the silicon particles occupy the cell boundaries. Such changes in the structural and phase states of the materials response on their mechanical characteristics. To characterize the surface properties, the microhardness, wear parameter, and friction coefficient values are determined directly on the irradiated surface for all modification variants. As shown, the irradiation of the material surface with an intensive electron beam increases wear resistance and microhardness of the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys.

Thermal Spray Processing of WC-Co Nanomaterials

2000 ◽  
Author(s):  
J. Voyer ◽  
B.R. Marple
Keyword(s):  
Phase Composition ◽  
Recent Work ◽  
Phase Analysis ◽  
Thermal Spraying ◽  
Volume Percent ◽  
Wear Properties ◽  
Lower Porosity ◽  
Hvof Thermal Spraying ◽  
Spray Processing ◽  
Sprayed Coatings

Abstract WC-Co based cermets are extensively used in wear applications due to their hardness and toughness. Recent work has demonstrated the potential for using nanoscale constituents to improve the wear properties of these materials. In the present study, two WC-Co powders containing a nanosized WC phase were used to produce coatings by HVOF thermal spraying. These powders had similar properties except for the volume percent binder present: WC-8C0 and WC-12Co. The thermal spraying conditions were varied in order to identify their effect on the microstructure, properties and phase composition of the sprayed coatings. The as-sprayed coatings possess porosity values ranging between 1% and 2% and microhardness values (HV100) from 1150 to 1550, which are quite similar to values obtained for conventionally sized WC-based coatings. For all the coatings, phase analysis indicated significant degradation of the WC phase to produce W2C, W, CO3W3C and Co6W3C. For some spray conditions, even WO3 phase was found in the coatings. The JP-5000 HVOF system produces coatings with lower porosity, similar microhardness values and, more importantly, with lower WC degradation than the coatings produced with the DJ-2700.

Formation of structure, phase composition and properties of electro explosion resistant coatings using electron-beam processing

2014 ◽  
Author(s):  
Denis A. Romanov ◽  
Kirill V. Sosnin ◽  
Evgenij A. Budovskikh ◽  
Viktor E. Gromov ◽  
Alexander P. Semin
Keyword(s):  
Electron Beam ◽  
Phase Composition ◽  
Electron Beam Processing ◽  
Structure Phase

Electrochemical Deposition of Fluoridated Calcium Phosphate Thin Film on Titanium Substrates

2008 ◽  
Vol 47-50 ◽  
pp. 1387-1390 ◽  
Author(s):  
Xiang Ge ◽  
Fu Zeng Ren ◽  
Yang Leng
Keyword(s):  
Thin Film ◽  
Calcium Phosphate ◽  
Dental Implants ◽  
Titanium Substrate ◽  
Titanium Implants ◽  
Connective Tissues ◽  
Percutaneous Device ◽  
Fluorine Ions ◽  
Film Synthesis ◽  
Titanium Substrates

Percutaneous type of orthopedic and dental implants requires not only a good adhesion with bone, but also the ability to form good attachment and seal with connective tissues and skins. Currently, the skin-seal of such implants still remains as a problem to be resolved. Electrochemical processing was used to modify the surface of titanium implants in order to improve the ability of anti-bacteria infection and skin seal around the implants by synthesizing a fluoridated calcium phosphate thin film on titanium substrate. The surface of titanium was cathodically treated in an electrochemical cell. A thin film of about 80 nm thickness was deposited on the titanium surface by controlling the treatment parameters. The dense and gel-like film was composed of calcium phosphate and fluorine ions. Fluorine ion has the anti-bacteria property and could help to improve the skin seal around the percutaneous device. The electrochemical method of fluoridated calcium phosphate thin film synthesis will provide an alternative method for surface treatment of orthopedic and dental implants.

scholarly journals Biomimetic Collagen/Zn2+-Substituted Calcium Phosphate Composite Coatings on Titanium Substrates as Prospective Bioactive Layer for Implants: A Comparative Study Spin Coating vs. MAPLE

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 692 ◽  
Author(s):  
Ionela Andreea Neacsu ◽  
Laura Vasilica Arsenie ◽  
Roxana Trusca ◽  
Ioana Lavinia Ardelean ◽  
Natalia Mihailescu ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Comparative Study ◽  
Spin Coating ◽  
Composite Coatings ◽  
Titanium Implants ◽  
Laser Evaporation ◽  
Mineralization Process ◽  
Ftir Microscopy ◽  
Titanium Substrates

Synthesis of biomimetic materials for implants and prostheses is a hot topic in nanobiotechnology strategies. Today the major approach of orthopaedic implants in hard tissue engineering is represented by titanium implants. A comparative study of hybrid thin coatings deposition was performed by spin coating and matrix-assisted pulsed laser evaporation (MAPLE) onto titanium substrates. The Collagen-calcium phosphate (Coll-CaPs) combination was selected as the best option to mimic natural bone tissue. To accelerate the mineralization process, Zn2+ ions were inserted by substitution in CaPs. A superior thin film homogeneity was assessed by MAPLE, as shown by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) microscopy. A decrease of P-O and amide absorbance bands was observed as a consequence of different Zn2+ amounts. A variety of structural modifications of the apatite layer are then generated, which influenced the confinement process towards the collagen template. The in-vitro Simulated Body Fluid (SBF) assay demonstrated the ability of Coll/Zn2+-CaPs coatings to stimulate the mineralization process as a result of synergic effects in the collagen-Zn2+ substituted apatite. For both deposition methods, the formation of droplets associated to the growth of CaPs particulates inside the collagen matrix was visualized. This supports the prospective behavior of MAPLE biomimetic coatings to induce mineralization, as an essential step of fast implant integration with vivid tissues.

Modification of the Titanium Surface Layer by the Yttrium

2015 ◽  
Vol 1085 ◽  
pp. 63-67
Author(s):  
Yurii F. Ivanov ◽  
Natalja Popova ◽  
Mark Kalashnikov ◽  
Victor Gromov ◽  
Evgeniy Budovskih ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Phase Composition ◽  
Friction Coefficient ◽  
Wear Rate ◽  
High Intensity ◽  
Titanium Surface ◽  
Mechanical And Tribological Properties ◽  
Modified Layer ◽  
Combined Technique

Modification of a titanium surface layer with yttrium using the combined technique of electroexplosive doping and the subsequent irradiation by a high-intensity electron beam is carried out. The studies on the structure, the element and the phase composition, mechanical and tribological properties of the doped layer are carried out. Formation of a multiphase submicron-nanocrystalline eutectic is revealed. A multifold increase in the microhardness, a decrease in the friction coefficient and the wear rate of the modified layer is established.

Bioactive and Antibacterial Ag-AgCl-TiO2 Coating on Titanium Implants

2016 ◽  
Vol 852 ◽  
pp. 1213-1219 ◽  
Author(s):  
Tian Tian ◽  
Liu Hui ◽  
Gu Ming Jun ◽  
Jin Ying
Keyword(s):  
Bacterial Adhesion ◽  
Antibacterial Property ◽  
Titanium Implants ◽  
Material Surface ◽  
X Ray Diffraction ◽  
E Coli ◽  
Implant Material ◽  
Titanium Substrates ◽  
Soaking Test

In this work, Ag-AgCl-TiO2 coating was fabricated on titanium substrates to obtain an implant material having excellent antibacterial property and bioactivity. The coating was investigated by scanning electron microscopy and X-ray diffraction. The bioactivity of coatings was examined by simulated body fluid soaking test. To verify the susceptibility of implant material surface to bacterial adhesion, S. aureus (Sau), E. coli (Eco), K. pneumoniae (Kpn), P. Aeruginosa (Pae), four types of major pathogen were chosen for in vitro antibacterial analyses. The results showed that Ag-AgCl-TiO2 coating had excellent antibacterial property and bioactivity.

Effect of Electron Beam Scanning on Ni60A Alloy Layer of H13 Steel Surface

2013 ◽  
Vol 815 ◽  
pp. 61-66
Author(s):  
De Qiang Wei ◽  
Zhen Lei Zhao ◽  
Rong Wang
Keyword(s):  
Electron Beam ◽  
Thermal Spraying ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Steel Matrix ◽  
H13 Steel ◽  
Columnar Crystal ◽  
Dendritic Crystal ◽  
Electron Scanning Microscope ◽  
Energy Disperse Spectroscopy

Prepare Ni60A on the H13 steel matrix in thermal spraying. Then, the alloy layer is treated with electron beam in multichannel lapping. Microstructure, the direction of grain growth, the situation of crack initiation on surface modification are analyzed and researched by optical microscope,electron scanning microscope,energy disperse spectroscopy. Experimental results show that the alloy layer which is scan with an electron beam is fuse together with the steel matrix. The organizations of the strengthened layer are dendritic crystal and columnar crystal. Moreover, the grain refinement is well done. Some microcosmic or macroscopic crack appear in the scan regions.

The Structure and Wear Resistance of the Surface Layers Obtained by the Atmospheric Electron Beam Cladding of TiC on Titanium Substrates

2014 ◽  
Vol 682 ◽  
pp. 14-20 ◽  
Author(s):  
Olga G. Lenivtseva ◽  
Daria V. Lazurenko ◽  
Vitaliy V. Samoylenko
Keyword(s):  
Wear Resistance ◽  
Electron Beam ◽  
Titanium Carbide ◽  
Volume Fraction ◽  
High Strength ◽  
Carbide Powder ◽  
Surface Layers ◽  
Matrix Morphology ◽  
Titanium Substrates ◽  
Carbide Particles

In this study the structure and properties of surface layers obtained on cp-titanium workpieces by non-vacuum electron beam cladding of titanium carbide powder were investigated. The structure of modified materials was examined by optical microscopy and scanning electron microscopy. It was shown that the cladded layer had a high quality and thickness of about 2.3 mm. The cladded layer microstructure consisted of high-strength titanium carbide crystals distributed in titanium matrix. Morphology of titanium carbide particles and their volume fraction changed in the direction from the surface layer to the heat affected zone. The average microhardness value of the cladded layer was ~500 HV. Surface alloyed layers were of higher wear resistance compared to cp-titanium.

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