Search results for "Melting point"
showing 10 items of 97 documents
An anomalous wave formation at the Al/Cu interface during magnetic pulse welding
2020
This paper reports an anomalous wave formation at an Al/Cu bimetallic interface produced by magnetic pulse welding. The mechanism of the anomalous wave formation is investigated using both metallurgical characterization and the interface kinematics. It reveals that the anomalous wave is formed with the combination of the intermediate zone and the interdiffusion zone with a thickness of 70 nm, wherein the intermediate zone is caused by the local melting due to the high shear instability, and the interdiffusion zone is formed below the melting point of aluminum combined with ultrahigh heating and cooling rates of about 10^13 °C s^−1. A multiphysics simulation of impact welding has been perfor…
Studies on antimony trifluoride in thiocyanate salt matrices. Evidence for the formation of fluoro-thiocyanato anti-mony(III) species
1990
Abstract Antimony trifluoride can be dissolved in fused KNCS or NH4NCS giving yellow-orange solutions which are stable only for a short time just above their melting point. Infrared an Mossbauer results on solidified samples reveal the formation of mixed fluoro-thiocyanato antimony(III) species and indicate a different behaviour in the two matrices.
Extended Investigation of the Aqueous Self-Assembling Behavior of a Newly Designed Fluorinated Surfactant
2009
The physicochemical behavior of the newly synthesized fluorinated 5-hydroxyamino-3-perfluoroheptyl-1,2,4-oxadiazin-6-one (PFHO) surfactant was investigated. Thermal analysis showed that the pure surfactant is thermally stable under an inert atmosphere to 135 degrees C, which is several degrees higher than the melting point (99 degrees C). PFHO is rather active at the water/air interface where it assumes a standing up configuration. It exhibits an enhanced self-assembling behavior; accordingly, the critical micellar concentrations at some temperatures are 2 orders of magnitude lower than those of a similar surfactant having the same phobicity, such as sodium perfluorooctanoate. Even in the d…
4-hydroxy-ONN-azoxybenzene
2000
The oxidation of 4-hydroxyazobenzene provided a mixture of two azoxy compounds, which were separated by column chromatography. The isomer with the higher melting point appeared to belong to the α (ONN) series, as determined by X-ray diffraction. The molecule, C12H10N2O2, is almost planar. The benzene rings are twisted by 11.7 (2) (substituted) and 4.1 (1)° (unsubstituted) with respect to the ONN plane. The molecules are connected to one another by strong O—H⋯O hydrogen bonds forming chains extended along [001], which are bound by much weaker C—H⋯O hydrogen bonds forming layers in the bc plane.
Die Kristallisation von Mehrkomponentensystemen aus hochpolymeren Stoffen
1977
Es wird untersucht, welche Anderungen im Kristallisationsverhalten hochpolymerer Stoffe auftreten, wenn man von einem Einkomponentensystem auf ein Mehrkomponentensystem ubergeht. Beispiele fur Mehrkomponentensysteme sind Homopolymere mit einer breiten Molekulargewichtsverteilung, Mischungen aus verschiedenen Homopolymeren, gequollene Polymere, Blockcopolymere und statistische Copolymere. Das Auftreten einer Molekulargewichtsverteilung ausert sich vor allem bei einer Kristallisation mit gestreckten Ketten, und zwar in der Weise, das eine Fraktionierung nach Molekullangen auftritt. Des weiteren bewirkt sie eine Verbreiterung des Schmelzbereichs. Die Anwesenheit eines zweiten nichtkristallisie…
A vacuum cell for obtaining clean surfaces on liquid low melting point metals
1997
Abstract Clean oxide film-free surface of liquid gallium was obtained in a sealed vacuum cell with a glass lid for observation. The cell was evacuated to high vacuum (10 -4 Pa) before admission of liquid and sealing. The surface contamination was about 2–5% of the free area and did not exhibit noticeable increase during several months of storing and employing the cell. The cell described allows observation of surface flows, capillary phenomena and crystallization processes under different conditions.
Crystal and molecular structure of anhydrous betaine, (CH3)3NCH2CO2
1999
Abstract 1–Carboxy–N,N,N–trimethylmethanamanium inner salt or anhydrous betaine, (CH3)3NCH2CO2, FW=117.15 gmol −1 , crystallizes in the orthorhombic space group Pnma with a=14.544(2) A , b=6.859(3) A , c=6.131(1) A , V=611.7(3) A 3 , Z=4, D x =1.27 Mgm −3 , λ (MoK α )=0.71073 A , μ =0.091 mm −1 . The structure was resolved by direct methods and refined by least-square calculations to R=0.038 for 531 reflections. Observed changes in bond angles imply that there is a repulsion between nitrogen and oxygen. The melting point (measured at onset) is 570 K. FTIR spectra of anhydrous betaine and monohydrate were recorded. Clear differences were found between the two compounds based on infrared (i.r…
Crystal structures and thermal behavior of bis[dibenzyldimethylammonium]CuBr4, bis[dibenzyldimethylammonium]CuCl4 and bis[dimethyldi(2-phenylethyl)am…
2006
Abstract Bis[dibenzyldimethylammonium]CuBr4, bis[dibenzyldimethylammonium]CuCl4 and bis[dimethyldi(2-phenylethyl)ammonium]CuBr4 were crystallized from acetonitrile and/or dilute HX solutions. Five different kinds of single crystals were obtained. In the case of bis[dibenzyldimethylammonium]CuX4 (X=Br or Cl), the acetonitrile molecules cocrystallized into the crystal structure when acetonitrile solution was used. As a result, the isomorphic structures of Bis[dibenzyldimethylammonium]CuX4·0.5 CH3CN (X=Br or Cl) in monoclinic space group P21/n were obtained. When a dilute HX solution was used, the bis[dibenzyldimethylammonium]CuX4 (X=Br or Cl) crystallized without solvent molecules. The formed…
Thermal behaviour of anhydrous, dihydrate and (2/1) ethanol forms of 1-O-α-d-glucopyranosyl-d-mannitol
1998
Abstract The melting points of anhydrous 1-O-α- d -glucopyranosyl- d -mannitol, 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and a new compound, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) were determined using differential scanning calorimetry. The melting onset values were 169.2 (3), 104.3 (18) and 158.7 (9), respectively, and the melting peak values were 171.4 (5), 107.9 (15) and 160.1 (6), respectively. 1-O-α- d -glucopyranosyl- d -mannitol dihydrate and 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) decompose to anhydrous form when heated at slow heating rates. According to TG-FTIR measurements, 1-O-α- d -glucopyranosyl- d -mannitol-ethanol (2/1) lost its ethanol in the…
MoSi2 laser cladding—A new experimental procedure: double-sided injection of MoSi2 and ZrO2
2003
International audience; In the last decade, development of low density advanced material systems for service at temperatures up to 1300 °C was one of the goals of many researches. This kind of material should mainly have moderate fracture toughness and should exhibit oxidation resistant behaviour at low and intermediate temperature. One of the most studied materials continues to be the intermetallic compound MoSi2. The molybdenum disilicide has been considered as an attractive candidate due to its melting point (2030 °C) and excellent oxidation resistance at high temperatures. The main problem associated with the MoSi2 layer synthesized using laser beam is the layer fragility. To avoid this…