Diffusion Niobizing of Titanium Grade 2 by Gas-Contact Method

2015 ◽  
Vol 669 ◽  
pp. 158-166
Author(s):  
Dariusz Bartkowski ◽  
Andrzej Mlynarczak ◽  
Adam Piasecki ◽  
Waldemar Matysiak ◽  
Michal Hatala ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Diffusion Layer ◽  
Powder Mixture ◽  
Diffusion Processes ◽  
Contact Method ◽  
Niobium Content ◽  
Structure Quality ◽  
Pure Niobium ◽  
Titanium Grade ◽  
Geometric Surface

The work presents results of diffusion niobizing of titanium Grade 2 by gas-contact method. Microhardness, thickness, chemical composition and microstructure were investigation. Diffusion processes was carried out in a two powder mixture. First consisted of ferro-niobium, kaolin and ammonium chloride, second mixture contained pure niobium instead ferro-niobium. The processes were carried out at 950°C, 1000°C and 1050°C for 2, 4 and 6 hours. Due to the geometric surface structure quality and other properties like thickness or microhardness, the best diffusion layer was obtained using first powder mixture and following parameters: temperature 950°C and time of diffusion equal 2 hours. The diffusion layer established in these conditions, had structure of niobium solution in titanium, and niobium content of about 10%. Its hardness was 550 HV0.05 while thickness was 120 μm.

scholarly journals Formation of Intermediate Phases and Supersaturated Solid Solution in Al-Cu System during Diffusion

2018 ◽  
Vol 383 ◽  
pp. 31-35 ◽  
Author(s):  
Alexey Rodin ◽  
Nataliya Goreslavets
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
High Temperature ◽  
Chemical Composition ◽  
Low Temperature ◽  
Supersaturated Solid Solution ◽  
Diffusion Processes ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Intermediate Phases

The study of diffusion processes in the aluminum - copper system was carried out at the temperature 350 and 520 °C. Special attention was paid on the chemical composition of the system near Al/Cu interface. It was determined that the intermediate phases in the system, corresponding to the equilibrium phase diagram, were not formed at low temperature. At high temperature the intermediate phases forms starting with Cu - rich phases. In both cases supersaturated solid solution of copper in aluminum could be observed near the interface.

Molecular Diffusion Processes in Crystalline Microporous Materials

1998 ◽  
Vol 527 ◽  
Author(s):  
G. Sastre ◽  
A. Corma ◽  
C. R. A. Catlow
Keyword(s):  
Molecular Dynamics ◽  
Chemical Composition ◽  
Diffusion Coefficients ◽  
Molecular Diffusion ◽  
Diffusion Processes ◽  
Diffusion Path ◽  
Microporous Structure ◽  
Microporous Material ◽  
Para Xylene ◽  
Channel Systems

ABSTRACTAtomistic Molecular Dynamics are used to simulate diffusion of hydrocarbons inside the microporous structure of siliceous zeolite CIT-I, with chemical composition SiO2. CIT-1 is a crystalline microporous material containing channels formed by rings containing 12 and 10 Si atoms (Figure 1). The dimensions of these two channel systems are sufficient to cause substantial differences in the diffusion of para-xylene and ortho-xylene. Diffusion coefficients as a function of loading of each isomer, and activation energies have been calculated from the simulations. The effect of the isomer size in the diffusion path is also analysed.

Effect of Heat-Treatment on the Interface Microstructure of Explosively Welded Stainless Steel – Bronze Composite

2014 ◽  
Vol 698 ◽  
pp. 495-500 ◽  
Author(s):  
Iuliia N. Maliutina ◽  
Vyacheslav I. Mali ◽  
Ksenia A. Skorokhod ◽  
Anatoly A. Bataev
Keyword(s):  
Stainless Steel ◽  
Diffusion Layer ◽  
Weld Joint ◽  
Diffusion Processes ◽  
Iron Concentration ◽  
Mixing Zone ◽  
Structural Variations ◽  
Heat Treated ◽  
The Difference ◽  
Interface Mixing

Analysis of structural variations taking place at the stainless steel (09Cr18Ni10Ti) - bronze (CuBe2Ni) interface obtained by explosive welding was conducted in the current work. The produced weld joint was post heat-treated in the temperature range from 500 to 800 °С. Microstructural characterizations were carried out using optical and scanning electron microscopy. The results of the analysis revealed the presence of 2 zones at the interface: mixing zone of bronze and stainless steel and a diffusion zone. The diffusion processes in the weld joint during heating were studied by the energy-dispersive analysis (EDX). EDX studies revealed that at 800 °С copper contained in bronze completely migrated from the diffusion layer to the mixing zone whereas iron concentration, on the contrary, increased in the diffusion layer. Voids appeared in the mixing zone of stainless steel and bronze due to the difference of diffusion coefficients of basic elements in the composite.

Vacuum Repair Brazing of the Inconel 939 Superalloy

2008 ◽  
Vol 51 ◽  
pp. 71-78 ◽  
Author(s):  
D.K. Wang ◽  
H.C. Wu ◽  
R.K. Shiue ◽  
C. Chen
Keyword(s):  
Chemical Composition ◽  
Oxide Film ◽  
Oxidation Resistance ◽  
Powder Mixture ◽  
Eutectic Temperature ◽  
Early Stage ◽  
Isothermal Solidification ◽  
Catastrophic Failure ◽  
Powder Mixtures ◽  
Residual Melt

Vacuum repair brazing of Inconel 939 using various ratios of DF3 and Rene 80 powder mixtures has been performed in this study. The porosity of the brazed zone is decreased as the amount of DF3 is increased in the powder mixture. At least four phases are observed in the brazed zone including chromium borides, sparse carbides, Ni-rich matrix and eutectic phases. Primary chromium borides are widely observed at the early stage of repair brazing. Dissolution of the Ni from the Rene 80 powder into the molten braze results in isothermal solidification of the residual melt. The chemical composition of the residual melt subsequently moves towards the lowest eutectic temperature, and the eutectic is finally formed in brazing. The oxidation resistance test is performed at 1000oC. Extensive spalling of the oxide film begins at 144 h, and catastrophic failure of the oxide film is observed at 1272 h. The oxidation resistance of the brazed zone is significantly degraded due to the formation of chromium borides in the brazed zone.

Characterization of recycled TiC and its influence on the microstructural, tribological, and corrosion properties of a TiC-reinforced metal matrix composites

2017 ◽  
Vol 51 (26) ◽  
pp. 3611-3621 ◽  
Author(s):  
A Mohr ◽  
A Röttger ◽  
W Theisen
Keyword(s):  
Particle Size ◽  
Corrosion Resistance ◽  
Chemical Composition ◽  
Metal Matrix ◽  
Diffusion Processes ◽  
Wear Behavior ◽  
Material Behavior ◽  
Corrosion Properties ◽  
Hard Particles ◽  
Wear And Corrosion

Ferro-Titanit® is a metal matrix composite (MMC) with a high wear and corrosion resistance. It contains TiC as hard particles on account of their high hardness, good corrosion resistance, and low density. This wear- and corrosion-resistant material is amenable to machining in the soft-annealed state, which gives rise to chips containing a large amount of the expensive TiC hard particles. Due to the cost of TiC, there is great interest in recycling the TiC from these chips so that it can be reused in the production of further Ferro-Titanit® materials. In this study, the recycled TiC [(Ti,X)C] is investigated with regard to morphology, particle size, chemical composition, and phases, and the results were compared to industrially produced TiC. In the next step, the (Ti,X)C was reused in the production of new Ferro-Titanit®. The Ferro-Titanit® reinforced with (Ti,X)C was also characterized with respect to microstructure, wear behavior, and corrosion resistance. Our investigations identified a change in the chemical composition of the TiC as a result of diffusion processes and a decrease in TiC particle size with respect to the initial state. The change in morphology and size of TiC during the recycling process influences the microstructure and the material behavior of the MMC containing recycled TiC.

Thermodynamic effects after Diode and Er:YAG laser irradiation of grade IV and V titanium implants placed in bone – an ex vivo study. Preliminary report

2016 ◽  
Vol 61 (5) ◽  
Author(s):  
Jacek Matys ◽  
Ute Botzenhart ◽  
Tomasz Gedrange ◽  
Marzena Dominiak
Keyword(s):  
Chemical Composition ◽  
Laser Power ◽  
Ex Vivo ◽  
Titanium Implants ◽  
Implant Surface ◽  
Laser Parameters ◽  
Thermodynamic Effects ◽  
Titanium Grade ◽  
Time Required ◽  
Ex Vivo Study

AbstractMany inserted implants are affected by peri-implantitis. The aim of our study was to evaluate increases in implant temperature, depending on the diameter and chemical composition of implants. In particular we measured the time it takes for the temperature of an implant to rise by 10°C and evaluated laser power settings required to prevent thermal injury when an implant surface is decontaminated during the treatment of peri-implantitis. The study analysed six implants placed in porcine ribs and divided into two groups according to their diameter and chemical composition (grade IV and grade V titanium). The implants were irradiated with Diode and Er:YAG lasers using different laser parameters. The temperature was measured with a K-type thermocouple. The temperature on the implant surface rose as the laser power increased and the implant diameter decreased. The time required to increase the temperature of an implant by 10°C was less than it was for titanium grade IV. The temperature gradient was below 10°C for all implants treated using a laser power up to 1 W. It is important to choose the correct laser parameters, depending on the chemical composition and diameter of the implant, so that decontamination of the implant surface is thorough, effective and safe.

scholarly journals Fabrication and characterisation of porous, calcium enriched coatings on titanium after plasma electrolytic oxidation under DC regime

2017 ◽  
Vol 17 (4) ◽  
pp. 55-67 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
K. Pietrzak ◽  
P. Sadlak ◽  
J. Valíček
Keyword(s):  
Surface Roughness ◽  
Chemical Composition ◽  
Plasma Electrolytic Oxidation ◽  
Calcium Nitrate ◽  
Roughness Parameters ◽  
Porous Coatings ◽  
Electrolytic Oxidation ◽  
Titanium Grade ◽  
Plasma Electrolytic ◽  
Peo Coatings

Abstract The purpose of this work is to produce and characterize (chemical composition and roughness parameters) porous coatings enriched in calcium and phosphorus on the titanium (CP Titanium Grade 2) by plasma electrolytic oxidation. As an electrolyte, a mixture of phosphoric acid H3PO4 and calcium nitrate Ca(NO3)2·4H2O was used. Based on obtained EDS and roughness results of PEO coatings, the effect of PEO voltages on the chemical composition and surface roughness of porous coatings was determined. With voltage increasing from 450 V to 650 V, the calcium in PEO coatings obtained in freshly prepared electrolyte was also found to increase. In addition, the Ca/P ratio increased linearly with voltage increasing according to the formula Ca/P = 0.035·U+0.176 (by wt%) and Ca/P = 0.03·U+0.13 (by at%). It was also noticed that the surface roughness increases with the voltage increasing, what is related to the change in coating porosity, i.e. the higher is the surface roughness, the bigger are pores sizes obtained.

Antimicrobial properties and chemical composition of liquid and gaseous phases of essential oils

2015 ◽  
Vol 69 (8) ◽  
Author(s):  
Kamil Křůmal ◽  
Nela Kubátková ◽  
Zbyněk Večeřa ◽  
Pavel Mikuška
Keyword(s):  
Chemical Composition ◽  
Essential Oils ◽  
Antimicrobial Properties ◽  
Volatile Components ◽  
Contact Method ◽  
Linalyl Acetate ◽  
Lavandula Angustifolia ◽  
Cinnamomum Zeylanicum ◽  
Bacteria And Fungi ◽  
Main Components

AbstractThe antimicrobial properties of fifteen essential oils (EOs) tested on seventeen microorganisms were determined using the vapour-agar contact method. The most effective EOs (i.e. Lavandula angustifolia, Cymbopogon nardus, Citrus aurantifolia, Juniperus communis, Myrtus communis and Cinnamomum zeylanicum), whose volatile components afforded the best antimicrobial properties, were selected for a detailed study of chemical composition. All these six EOs contained one to three main components that presented 67-91 mass % of total mass of a corresponding essential oil. The amount of other components was much lower (less than 5 mass %). The volatile components of Lavandula angustifolia exhibited the most effective antimicrobial properties because they completely inhibited the tested bacteria and fungi within 3 days and 1 week, respectively. The components of Lavandula angustifolia with the highest concentration in the gaseous phase were linalool (99.0 ppmv), eucalyptol (44.9 ppmv), linalyl acetate (25.9 ppmv), myrcene (22.2 ppmv), β-trans-ocimene (19.7 ppmv), camphor (16.7 ppmv) and limonene (14.9 ppmv).

Preparation and oxidation of Al4SiC4

2002 ◽  
Vol 17 (4) ◽  
pp. 774-778 ◽  
Author(s):  
Osamu Yamamoto ◽  
Motoko Ohtani ◽  
Tadashi Sasamoto
Keyword(s):  
Chemical Composition ◽  
Carbon Black ◽  
Powder Mixture ◽  
Single Phase ◽  
Heating Temperature ◽  
Mass Gain ◽  
Molar Ratio ◽  
Argon Gas ◽  
Two Phases ◽  
Aluminum Silicon

Single-phase Al4SiC4 was successfully synthesized by heating the powder mixture of aluminum, silicon, and carbon black in the molar ratio corresponding to the chemical composition of Al4SiC4 with a small amount of triethanolamine (TEA) above 1200 °C in argon gas. Without TEA, two phases of Al4C3 and SiC were formed, irrespective of the heating temperature. The marked mass gain by oxidation of Al4SiC4 was observed with forming Al2O3 and SiO2 in the range of 850 to 1150 °C, which slightly increased above 1150 °C. At 1600 °C, mullite was formed by the reaction between Al2O3 and SiO2.

Influence of Ultrafine-Grained Structure of Martensitic and Austenitic Steels on Diffusion Processes at Low-Temperature Ion Nitriding

2018 ◽  
Vol 383 ◽  
pp. 167-172
Author(s):  
Uldash Gamirovich Khusainov ◽  
Kamil Nurulaeyevich Ramazanov ◽  
Roman Sergeevich Esipov
Keyword(s):  
Growth Rate ◽  
High Pressure ◽  
Low Temperature ◽  
Diffusion Layer ◽  
Diffusion Processes ◽  
Austenitic Steels ◽  
Ion Nitriding ◽  
Ultrafine Grained Structure ◽  
Ultrafine Grained ◽  
Before And After

The paper discusses the influence of ultrafine-grained structure of martensitic and austenitic steels on diffusion processes at low-temperature ion nitriding. The microstructure of ultrafine-grained steels was analysed before and after nitriding. Depth distributions of microhardness are given depending on the class and structure of steels. The study proves that ultrafine-grained structure of steels obtained by high pressure deformation by torsion allows an increased growth rate of the diffusion layer at nitriding.

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