scholarly journals Crystal plasticity and in-situ diffraction-based determination of the dislocation strengthening and load-sharing effects of precipitates in Mg alloy, AZ91

Materialia ◽  
2019 ◽  
Vol 6 ◽  
pp. 100308 ◽  
Author(s):  
J.J. Bhattacharyya ◽  
S.R. Kada ◽  
M.R. Barnett ◽  
S.R. Agnew
Keyword(s):  
Crystal Plasticity ◽  
Load Sharing ◽  
Mg Alloy ◽  
Alloy Az91 ◽  
Dislocation Strengthening ◽  
In Situ Diffraction

In Situ Mg2Si Reinforced Mg Alloy Synthesized in Mg-SiO2 System

2010 ◽  
Vol 146-147 ◽  
pp. 1775-1779
Author(s):  
Dan Huang ◽  
Yan Li Wang ◽  
Ying Wang ◽  
Hong Bao Cui ◽  
Xue Feng Guo
Keyword(s):  
Thermodynamic Analysis ◽  
Equilibrium Diagram ◽  
Mg Alloy ◽  
Experimental Temperature ◽  
Chinese Script ◽  
Solidification Condition ◽  
Sio2 System ◽  
Primary Mg2si

The thermodynamic analysis in Mg-SiO2 system was conducted for the determination of the priority reaction at experimental temperature. Then, Mg2Si reinforced Mg alloy was synthesized through reaction in Mg-SiO2 system at 730°C, whose Si mass fraction is up to approximately 10%. The thermodynamic analysis and microstructure investigation results show, that generation of reinforcing phase of Mg2Si in Mg alloy from the reaction in Mg-SiO2 system is feasible with lower free energy than that in Mg-Si at the same temperature; and under the experimental temperature and solidification condition, the microstructure of Mg-10Si alloy is composed of coarse primary Mg2Si dendrite crystal, Chinese script type eutectic Mg2Si, and α–Mg phase, the formation of α–Mg holes is resulted from the relatively high cooling rate leading to a deviation from the equilibrium diagram during solidification.

scholarly journals Determination of Temperature-Dependent Elastic Constants of Steel AISI 4140 by Use of In Situ X-ray Dilatometry Experiments

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2378
Author(s):  
Dominik Kiefer ◽  
Jens Gibmeier ◽  
Andreas Stark
Keyword(s):  
Elastic Constants ◽  
High Energy ◽  
Lattice Plane ◽  
Temperature Dependent ◽  
X Ray ◽  
Aisi 4140 ◽  
Steel Aisi ◽  
In Situ Diffraction

In situ dilatometry experiments using high energy synchrotron X-ray diffraction in transmission mode were carried out at the high energy material science beamline P07@PETRAIII at DESY (Deutsches Elektronen Synchrotron) for the tempering steel AISI 4140 at defined mechanical loading. The focus of this study was on the initial tempering state ( f e r r i t e ) and the hardened state ( m a r t e n s i t e ). Lattice strains were calculated from the 2D diffraction data for different h k l planes and from those temperature-dependent lattice plane specific diffraction elastic constants ( D E C s ) were determined. The resulting coupling terms allow for precise stress analysis for typical hypoeutectoid steels using diffraction data during heat treatment processes, that is, for in situ diffraction studies during thermal exposure. In addition, by averaging h k l specific Y o u n g ′ s m o d u l i and P o i s s o n r a t i o s macroscopic temperature-dependent elastic constants were determined. In conclusion a novel approach for the determination of phase-specific temperature-dependent DECs was suggested using diffraction based dilatometry that provides more reliable data in comparison to conventional experimental procedures. Moreover, the averaging of lattice plane specific results from in situ diffraction analysis supply robust temperature-dependent macroscopic elastic constants for martensite and ferrite as input data for heat treatment process simulations.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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