Deposition of Superhard Ti–C–N Plasma Coatings in Nitrogen Atmosphere

2021 ◽  
Vol 12 (3) ◽  
pp. 727-730
Author(s):  
D. Yu. Gerasimov ◽  
A. A. Sivkov
2020 ◽  
Vol 5 ◽  
pp. 44-48
Author(s):  
D.Yu. Gerasimov ◽  
◽  
A.A. Sivkov ◽  

The possibility of obtaining a superhard plasma coating based on titanium, nitrogen and carbon on a metal substrate in a nitrogen atmosphere is shown. The coatings were deposited in one short-term accelerator operation cycle under the action of a hyperspeed jet of electroerosive Ti-containing plasma on the substrate surface. It has been shown by SEM and XRD that nanostructured layers of titanium nitride and titanium carbonitride are formed, providing a high hardness of the coating. Plasma coatings deposited in a nitrogen atmosphere have a higher hardness (19.6 GPa) than coatings deposited in air (16.2 GPa), which is due to a higher content of nitride crystalline phases in the coating material. XRD data showed that the coherent-scattering region of crystalline phases in coatings deposited in an atmosphere of air and in a nitrogen atmosphere is ~10-40 nm, which confirms the nanostructuring of all crystalline phases presented in the coating.


Author(s):  
Takao Suzuki ◽  
Hossein Nuri

For future high density magneto-optical recording materials, a Bi-substituted garnet film ((BiDy)3(FeGa)5O12) is an attractive candidate since it has strong magneto-optic effect at short wavelengths less than 600 nm. The signal in read back performance at 500 nm using a garnet film can be an order of magnitude higher than a current rare earth-transition metal amorphous film. However, the granularity and surface roughness of such crystalline garnet films are the key to control for minimizing media noise.We have demonstrated a new technique to fabricate a garnet film which has much smaller grain size and smoother surfaces than those annealed in a conventional oven. This method employs a high ramp-up rate annealing (Γ = 50 ~ 100 C/s) in nitrogen atmosphere. Fig.1 shows a typical microstruture of a Bi-susbtituted garnet film deposited by r.f. sputtering and then subsequently crystallized by a rapid thermal annealing technique at Γ = 50 C/s at 650 °C for 2 min. The structure is a single phase of garnet, and a grain size is about 300A.


Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.


Author(s):  
Y. P. Lin ◽  
A. H. O’Reilly ◽  
J. E. Greedan ◽  
M. Post

In the basal planes of the orthorhombic YBa2Cu3O7-X compound with x=0.07, which has a Tc of around 90K, chains of copper-oxygen are formed along the [010] direction. Previous investigations on the variation of Tc with oxygen content have shown the existence of a plateau at Tc = 60K for x=0.3 to 0.4, suggesting the presence of a separate phase. This phase has also been identified to be orthorhombic, but with a 2x superlattice along [100] of the parent structure, and the superlattice has been attributed to the formation of alternating copper-oxygen and copper-vacancy chains. In our work, we have studied the chain ordering phenomenon by electron microscopy and neutron diffraction on samples with different oxygen contents. We report here some of our electron microscopy findings for samples with x=0.4.Powder samples of YBa2Cu3O7-X were prepared by controlled re-oxidation of previously reduced material. For electron microscopy, the sample was dry ground using a mortar and pestle in a dry nitrogen atmosphere without the use of any solvent and transferred dry onto holey carbon film for examination in a Philips CM12 microscope.


2019 ◽  
pp. 28-39
Author(s):  
Kalita V. I. ◽  
◽  
Radyuk A. A. ◽  
Komlev D. I. ◽  
Mikhailova A. B. ◽  
...  

2018 ◽  
pp. 34-45 ◽  
Author(s):  
V. I. Kalita ◽  
◽  
A. A. Radyuk ◽  
D. I. Komlev ◽  
A. B. Mikhailova ◽  
...  

2019 ◽  
pp. 53-64
Author(s):  
V. I. Kalita ◽  
◽  
G. A. Pribytkov ◽  
D. I. Komlev ◽  
V. V. Korzhova ◽  
...  

Author(s):  
I. N. Kravchenko ◽  
◽  
T. A. Chekha ◽  
A. A. Sevryukov ◽  
A. F. Slivov ◽  
...  

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.


2019 ◽  
Vol 70 (5) ◽  
pp. 1574-1578
Author(s):  
Cristian Neamtu ◽  
Bogdan Tutunaru ◽  
Adriana Samide ◽  
Alexandru Popescu

Electrochlorination constitutes an electrochemical approach for the treatment of pesticide-containing wastewaters. This study evaluated the electrochemical and thermal stability of four pesticides and the efficiency of electrochlorination to remove and detoxify the simulated polluted water with: Acetamiprid, Emamectin, Imidacloprid and Propineb. This study reports the experimental results obtained by cyclic voltammetry and electrolysis at constant current density in association with UV-Vis spectrophotometry. In saline waters this pesticides are electrochemical active and anodic peaks are registered in the corresponding voltammograms. After thermal combustion, in a gaseous nitrogen atmosphere, a residue ranging from 15 to 45 % is observed at 500 �C.


Sign in / Sign up

Export Citation Format

Share Document