Structure and properties of NiAl-Cr(Co,Hf) alloys prepared by centrifugal SHS casting. Part 1 – Room temperature investigations

2017 ◽  
Vol 690 ◽  
pp. 463-472 ◽  
Author(s):  
A.A. Zaitsev ◽  
Zh.A. Sentyurina ◽  
E.A. Levashov ◽  
Yu.S. Pogozhev ◽  
V.N. Sanin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structure And Properties ◽  
Centrifugal Shs ◽  
Shs Casting

scholarly journals Structure and Properties of Ln2MoO6 Oxymolybdates (Ln = La, Pr, Nd) Doped with Magnesium

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Ekaterina Orlova ◽  
Elena Kharitonova ◽  
Timofei Sorokin ◽  
Alexander Antipin ◽  
Nataliya Novikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
Hygroscopic Properties ◽  
Thermogravimetric Studies ◽  
Mg Doped

The literature data and the results obtained by the authors on the study of the structure and properties of a series of polycrystalline and single-crystal samples of pure and Mg-doped oxymolybdates Ln2MoO6 (Ln = La, Pr, Nd) are analyzed. Presumably, the high-temperature phase I41/acd of Nd2MoO6 single crystals is retained at room temperature. The reason for the loss of the center of symmetry in the structures of La2MoO6 and Pr2MoO6 and the transition to the space group I4¯c2 is the displacement of oxygen atoms along the twofold diagonal axes. In all structures, Mg cations are localized near the positions of the Mo atoms, and the splitting of the positions of the atoms of rare-earth elements is found. Thermogravimetric studies, as well as infrared spectroscopy data for hydrated samples of Ln2MoO6 (Ln = La, Pr, Nd), pure and with an impurity of Mg, confirm their hygroscopic properties.

Effect of Hydrogen Content on Structure and Properties of Sintering Body Utilizing TC21 Hydrogenated Powder

2012 ◽  
Vol 581-582 ◽  
pp. 777-781
Author(s):  
Ya Qiang Tian ◽  
Ying Li Wei ◽  
Hong Liang Hou ◽  
Xue Ping Ren
Keyword(s):  
Mechanical Property ◽  
Grain Size ◽  
Titanium Alloy ◽  
Yield Strength ◽  
Hydrogen Content ◽  
Room Temperature ◽  
Sintered Body ◽  
Compressive Yield Strength ◽  
Structure And Properties ◽  
Die Forming

The effect of hydrogenation on structure and properties of TC21 alloy by die forming and sintering using hydrogenated powder was researched by means of the room-temperature die forming and sintering in protection air to produce titanium alloy. The results show that the structure of TC21 titanium sintered body using hydrogenated powder with hydrogen content of 0.39 wt% by die forming and sintering is thinner and the density is higher than the others. The compression strength and compressive yield strength of TC21 sintered body with hydrogen content of 0.39 wt% are well. With hydrogen content increasing, the structure of TC21 production using hydrogenated powder by die forming and sintering gets well and the grain size becomes smaller. After annealing, the structure of TC21 titanium production gets more uniformity and refinement obviously, and the hydrogen content of TC21 alloy safety state is achieved. In the end, the density and mechanical property of TC21 titanium alloy sintered body with hydrogen content of 0.39wt % is the best.

Synthese, Kristallstruktur und Eigenschaften von 1,1,3,3,3-Pentaamino-1-oxo- 1λ5 ,3λ5-diphosphaz-2-en, (NH2)2(O)P-N=P(NH2)3 / Synthesis, Crystal Structure, and Properties of 1,1,3,3,3-Pentaamino-1-oxo-1λ5, 3λ5-diphosphaz-2-ene, (NH2)2(O)P-N=P(NH2)3

1996 ◽  
Vol 51 (8) ◽  
pp. 1079-1083 ◽  
Author(s):  
N. Stock ◽  
W. Schnick
Keyword(s):  
Crystal Structure ◽  
Thermal Properties ◽  
Room Temperature ◽  
Three Dimensional ◽  
Intermolecular Hydrogen Bonding ◽  
Structure And Properties ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network ◽  
Ray Methods

Coarse crystalline (NH2)2(O)P-N=P(NH2)3 is obtained from a NH3 saturated CH2Cl2 suspension of (NH2)2(O)P-N=P(NH2)3 NH4Cl at room temperature. (NH2)2(O)P-N=P(NH2)3·NH4Cl is synthesized by slow addition of Cl2(O)P-N=PCl3 to a solution of NH3 in CH2Cl2 at -78 °C. Excess NH4Cl is removed by treatment with HNEt2 followed by extraction with CH2Cl2. The crystal structure of (NH2)2(O)P-N=P(NH2)3 has been determined by single crystal X-ray methods (P21/c; a = 1462.8(3), b = 944.8(2), c = 1026.9(2) pm, β = 110.69(3)°; Z = 8). In the unit cell there are two crystallographically unique molecules. They form a three dimensional network by intermolecular hydrogen bonding interactions (N-H···N ≥ 313 pm. N-H···O ≥ 293 pm). The investigation of the thermal properties shows decomposition with evolution of NH3 above 80 °C.

scholarly journals Study of Cellulose Interaction with Concentrated Solutions of Sulfuric Acid

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Michael Ioelovich
Keyword(s):  
Sulfuric Acid ◽  
High Power ◽  
Room Temperature ◽  
Regenerated Cellulose ◽  
Structure And Properties ◽  
Optimal Conditions ◽  
Initial Sample ◽  
Concentrated Solutions ◽  
Crystallinity Degree ◽  
20 Nm

The effect of the concentration of sulfuric acid (SA) and temperature on structure and properties of cellulose (MCC) had been studied. Investigations showed that solubility of the initial sample at the room temperature increased gradually in the range of the acid concentration from 50 to 60 wt.% SA. When SA concentration reached 65 wt.%, then MCC sample dissolved completely. Cellulose regenerated from 65 wt.% SA had an amorphized structure and was characterized by high enzymatic digestibility. At increased temperature, 45°C, solubility of MCC in SA was raised, while yield and DP decreased. After treatment of MCC with hot 50–60 wt.% SA, the crystallinity degree of the obtained cellulose samples changed slightly, and these samples retained mainly the CI crystalline polymorph. However, when SA concentration reached 65 wt.%, then regenerated cellulose had CII crystalline polymorph, reduced crystallinity degree, and low DP. Using optimal conditions of the acidic treatment (57–60 wt.% SA, T = 45°C; t=1 h) in combination with the high-power disintegration permitted obtaining the CI nanocrystalline cellulose particles (NCP) having sizes 150–200 × 10–20 nm with the heightened yield (65–70%). These NCP can be used, for example, as reinforcing nanofillers for various composites.

scholarly journals Producing wear-resistant materials by SHS-casting with the application of centrifugal forces

2019 ◽  
Vol 64 (3) ◽  
pp. 275-285
Author(s):  
V. V. Klubovich ◽  
M. M. Kulak ◽  
V. G. Samolyotov ◽  
B. B. Khina
Keyword(s):  
Uniform Distribution ◽  
Measurement Instrument ◽  
High Wear Resistance ◽  
Centrifugal Forces ◽  
Wear Resistant ◽  
Soft Matrix ◽  
Reactive Iron ◽  
Centrifugal Shs ◽  
Strengthening Particles ◽  
Shs Casting

The paper is devoted to the problem of producing hard, wear-resistant materials by SHS-casting using centrifugal forces. We have developed a device for centrifugal SHS casting and initial compositions of the reactive iron-base charge. A technology for producing coatings, materials and final products with a non-uniform distribution of strengthening particles over the specimen volume has been developed and tested in industrial conditions. The microstructure and phase composition of the synthesized material with a non-uniform distribution of reinforcing particles is studied. The synthesized material implements the Charpy principle: dispersed hard carbide particles are distributed in a relatively soft matrix, which ensures high wear resistance. By means of SHS casting, billets were obtained for producing a measurement instrument, namely a plug-type gauge, which successfully passed industrial tests at OJSC “VIZAS”. The tests shown that the hardness of all synthesized samples was in the range from 63 to 68 HRC and the number of measurements per 1 micron of wear on a diameter of15 mm was 2500 to 2700. Hence, the developed method made it possible to significantly increase the service life of the measuring tool: by a factor of 1.5 to 2.

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