scholarly journals Analytical Electron Microscopy of Silicon Nitride Nanostructures Synthesized from the Vapor Phase

2019 ◽  
Vol 3 (1) ◽  
pp. 8
Author(s):  
Mariella Cortez Caillahua ◽  
F Moura ◽  
G Solorzano
Keyword(s):  
Silicon Nitride ◽  
Vapor Phase ◽  
Elevated Temperatures ◽  
Analytical Electron Microscopy ◽  
Chemical Properties ◽  
Specific Weight ◽  
Phase Reaction ◽  
Vapor Phase Reaction ◽  
Physical And Chemical ◽  
And Chemical Properties

Silicon nitride, Si3N4 is a covalent compound with excellent physical and chemical properties such as corrosion resistance, low-specific weight and good thermal conductivity at ambient and elevated temperatures. Such properties are very attractive in application as advanced ceramics and in semiconductor devise [1]. Nano sized amorphous silicon nitride powders were synthesized at 300 °C by precipitation from the vapor phase reaction of SiCl4 and NH3 and Ar as carrier gas. Solid ammonium halogenide is formed as by-product, in addition to silicon nitride powder.

Experimental Investigation on Grinding Temperature of Titanium Alloy

2014 ◽  
Vol 1027 ◽  
pp. 127-130 ◽  
Author(s):  
Bing Jun Hao ◽  
Zhi Gang Dong ◽  
Ren Ke Kang ◽  
Huan Wang ◽  
Ke Cao
Keyword(s):  
Titanium Alloy ◽  
Structural Changes ◽  
Thermal Damage ◽  
Elevated Temperatures ◽  
Chemical Properties ◽  
Grinding Temperature ◽  
Physical And Chemical Properties ◽  
Machine Material ◽  
Physical And Chemical ◽  
And Chemical Properties

Titanium alloy has been widely used in aeronautics and astronautics industry owing to its unique combinations of properties. The unique physical and chemical properties of titanium alloy make it a typical difficult-to-machine material. The elevated temperatures at the machining zones may cause thermal damage, residual stress and micro-structural changes in the surface layer of titanium alloy during grinding. In this study, grinding experiments were performed on the titanium alloy, and the grinding temperature was experimentally tested with the grindable thermocouples. The effects of the grinding parameters on the grinding temperature were analyzed. The grinding temperature rises with the increase of grinding speed and grinding depth.

Characteristics and Applications of Nanostructured Nitrides Synthesized by Vapor Phase Reactions

2005 ◽  
Vol 876 ◽  
Author(s):  
Gerald Ziegenbalg ◽  
Carsten Pätzold ◽  
Ute Ŝingliar ◽  
Rico Berthold
Keyword(s):  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Vapor Phase ◽  
Elevated Temperatures ◽  
Catalyst Support ◽  
Chemical Properties ◽  
Molar Ratio ◽  
Basic Catalyst ◽  
Metal Chlorides ◽  
Amorphous Silicon Nitride

AbstractGas phase ammonolysis of volatile metal chlorides at elevated temperatures is a favorable way to produce nitride or oxynitride nanopowders. Their composition as well as the physico-chemical properties is determined by reaction temperature, molar ratio of the reactants and the residence time of the gases in the reaction zone. Both single and multi component powders can be obtained. Typical particle sizes are in the range of 50 to 350 nm. The specific surface can reach values up to 300 m2/g. Microporous analysis revealed the presence of pores with a diameter between 0.6 and 0.7 nm in amorphous silicon nitride. The powders can be used, depending on the characteristics, as catalyst or basic catalyst support. The paper gives an overview about vapor phase synthesis of single and multi component nitrides as well as the use of amorphous silicon nitride as a basic catalyst support for dehydrogenation of propane.

scholarly journals Preparation of Fine Silicon Nitride Powders by Vapor Phase Reaction of Nitrogen Containing Organosilicon Compound with Ammonia

1987 ◽  
Vol 95 (1097) ◽  
pp. 91-95 ◽  
Author(s):  
Takasi SUZUKI ◽  
Takamasa KAWAKAMI ◽  
Takesi KOYAMA ◽  
Kansei IZAKI ◽  
Rieko NAKANO ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Vapor Phase ◽  
Organosilicon Compound ◽  
Phase Reaction ◽  
Vapor Phase Reaction

Optimization of reaction parameters for synthesis of amorphous silicon nitride powder by vapor phase reaction

2014 ◽  
Vol 40 (9) ◽  
pp. 14563-14568 ◽  
Author(s):  
Yong Kwon Chung ◽  
Jae Hong Koo ◽  
Shin A. Kim ◽  
Eun Ok Chi ◽  
Jee Hyun Hahn ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Vapor Phase ◽  
Phase Reaction ◽  
Nitride Powder ◽  
Reaction Parameters ◽  
Amorphous Silicon Nitride ◽  
Silicon Nitride Powder ◽  
Vapor Phase Reaction

Pressure Sintering of Si3N4 System for Near-Net Shape Forming

1989 ◽  
Vol 111 (2) ◽  
pp. 176-182
Author(s):  
Shyam K. Samanta ◽  
Harue Wada ◽  
Liya Wang
Keyword(s):  
Silicon Nitride ◽  
Hot Pressing ◽  
Chemical Properties ◽  
Theoretical Density ◽  
Physical And Chemical Properties ◽  
Sintering Process ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Physical And Chemical ◽  
And Chemical Properties

Yttria and alumina have been used with particular success, either singly or in combination, as densification aids for hot pressing and sintering of silicon nitride. To obtain desirable mechanical, physical, and chemical properties, it is necessary to minimize the addition of alumina as a densifying agent, however, very low amount of alumina additive reduces the possibility of sintering silicon nitride to high theoretical density. In this paper the authors have elucidated a sintering process which densifies silicon nitride to near theoretical density even with low amount of alumina doping.

Preparation of fine silicon nitride powders by vapor phase reaction of nitrogen containing organosilicon compound with ammonia

1987 ◽  
Vol 3 (4) ◽  
pp. 333-334
Author(s):  
Takasi Suzuki ◽  
Takamasa Kawakami ◽  
Takesi Koyama ◽  
Kansei Izaki ◽  
Rieko Nakano ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Vapor Phase ◽  
Organosilicon Compound ◽  
Phase Reaction ◽  
Vapor Phase Reaction

scholarly journals Contributions at Biodiversity, Physical and Chemical Properties Knowledge from Tinovul Mohos, in Ciucului Mountain

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Ioan PACURAR ◽  
Teodor RUSU ◽  
Doina CLAPA ◽  
Anca SOTROPA ◽  
Mircea DUNCA
Keyword(s):  
Chemical Properties ◽  
Specific Weight ◽  
Peat Moss ◽  
Physical And Chemical Properties ◽  
Organic Substances ◽  
Mineral Substance ◽  
Physical And Chemical ◽  
Acid Character ◽  
And Chemical Properties

Peat lands or histosoils occupy more than 6000 ha in Romania. Tinovul Mohos having more than 80 ha and a peat store more than 3 millions ton, is one of the most representative from Europe for his fauna and flora biodiversity. It is a peat land beggarly in nutritive and mineral substance, having a powerful acid character (pH 3,20-4,07).Tinovul Mohos is formed on the basis of peat moss Sphagnum, having a thickness of 10 m, more than 99% organic substances, specific weight between 0,69 and 0,84, and a percent of carbon 49-51%. Tinovul Mohos shelter many survival species like Lycopodium inundatum, Drosera obovata, Drosera intermedia, Andromeda polifolia, Meesea longiseta, Sparganium minimum, Calamagostris neglecta, Eriophorum gracile,Mitopus morio.

scholarly journals ANALYSİS OF THE İMPACT OF PHYSİCAL AND CHEMİCAL FEATURES OF THE NATURAL GAS TO THE PARAMETERS OF THE GAS TRANSPORT SYSTEM

2021 ◽  
Vol 11 (07) ◽  
pp. 22-28
Author(s):  
H.R.Gurbanov H.R.Gurbanov ◽  
A.N. Baghirov A.N. Baghirov
Keyword(s):  
Natural Gas ◽  
Chemical Properties ◽  
Specific Weight ◽  
Transportation System ◽  
Physical And Chemical Properties ◽  
Compressor Station ◽  
Associated Gas ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

Definition of the technological regimes of the natural gas transportation system is co-related with the physical and chemical features of the gas. The results of the chemical analyses of gas in the gas turbine compressor station are laid out in the article: various levels of changes of the composition of gas at various points are described. Technological losses of gas are determined, as the result of change in its specific weight in the process of compression, cooling down and separation at the compressor station. Gas losses in the sub water main gas pipelines are analyzed. Changes of the content of the gas carbonate in the composition of the gas are analyzed, its degradation alongside the pipeline and existence of the CO2 in the composition of the low-pressure oil associated gas is described in comparison with the high-pressure natural gas, which is 3,8 times more. The problems, caused by the presence of the gas carbonate in the composition of the natural gas, are highlighted. The physical properties of natural gas are characterized by its specific gravity, temperature, pressure, volume and other parameters, and chemical properties by its composition, stability of gas-forming components. It should be noted that the physical and chemical properties of gas vary within certain limits, depending on the time, both on the reservoir and on the same reservoir. Therefore, in order to regulate the parameters of the gas transportation system, it is necessary to periodically examine and take into account the physical and chemical properties of the gas. Keywords: Natural gas, carbon dioxide,compressor station, gas pipeline, gas well.

Sign in / Sign up

Export Citation Format

Share Document