The modelling of Ostwald-ripening during non-isothermal heat treatments resulting in temperature dependent matrix solubility of the precipitate forming elements: A further development of the LSW-theory

1996 ◽  
Vol 7 (1-2) ◽  
pp. 94-97 ◽  
Author(s):  
Simon Olive ◽  
Uwe Grafe ◽  
Ingo Steinbach
Keyword(s):  
Ostwald Ripening ◽  
Heat Treatments ◽  
Temperature Dependent ◽  
Lsw Theory ◽  
Isothermal Heat Treatments ◽  
Further Development

Ostwald Ripening of the InAsSbP/InAs(100) Quantum Dots in the Framework of the Modified LSW Theory

2017 ◽  
Vol 9 (2) ◽  
pp. 02025-1-02025-6
Author(s):  
B. V. Ivanskii ◽  
◽  
R. D. Vengrenovich ◽  
V. I. Kryvetskyi ◽  
Yu. M. Kushnir ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ostwald Ripening ◽  
Lsw Theory

scholarly journals Atomic Level Characterization of the Morphology of Phases in Chromindur Magnetic Alloys

1991 ◽  
Vol 232 ◽  
Author(s):  
M. K Miller ◽  
P. P. Camus ◽  
M. G. Hetherington
Keyword(s):  
Atom Probe ◽  
Heat Treatments ◽  
Miscibility Gap ◽  
Probe Field ◽  
Magnet Alloy ◽  
Two Phases ◽  
Isothermal Heat Treatments ◽  
Field Ion Microscope ◽  
Permanent Magnet Alloy

ABSTRACTThe atom probe field ion microscope has been used to characterize the morphology and determine the compositions of the iron-rich a and chromium-enriched α′ phases produced during isothermal and step cooled heat treatments in a Chromindur II ductile permanent magnet alloy. The good magnetic properties of this material are due to a combination of the composition of the two phases and the isolated nature and size of the ferromagnetic a phase. The morphology of the a phase is produced as a result of the shape of the miscibility gap and the step-cooled heat treatment and is distinctly different from that formed during isothermal heat treatments.

Simplified Analysis Methods for Primary Load Designs at Elevated Temperatures

2011 ◽  
Author(s):  
Peter Carter ◽  
T.-L. Sam Sham ◽  
R. I. Jetter
Keyword(s):  
Elevated Temperatures ◽  
Design Procedure ◽  
Inelastic Strain ◽  
Temperature Dependent ◽  
Perfectly Plastic ◽  
Reference Stress ◽  
Analysis Methods ◽  
Elastic Perfectly Plastic ◽  
Further Development ◽  
Primary Load

The use of “simplified” (reference stress) analysis methods is discussed and illustrated for primary load high temperature design. Elastic methods are the basis of the ASME Section III, Subsection NH primary load design procedure. There are practical drawbacks with this current NH approach, particularly for complex geometries and temperature gradients. The paper describes an approach which addresses these difficulties through the use of temperature-dependent elastic, perfectly-plastic analysis. Traditionally difficulties associated with discontinuity stresses, inelastic strain concentrations and multiaxiality are addressed. A procedure is identified to provide insight into how this approach could be implemented. Though preliminary in nature, it is intended to provide a basis for further development and eventual Code adaptation.

scholarly journals Investigation of the effect of isothermal heat treatments on mechanical properties of thermo-mechanically rolled S700MC steel grade

2020 ◽  
Vol 26 (1) ◽  
pp. 11-16
Author(s):  
Serkan Oktay ◽  
Paolo Emilio Di Nunzio ◽  
Mustafa Kelami Şeşen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Heat Treatments ◽  
Steel Grade ◽  
Secondary Hardening ◽  
Precipitation Kinetics ◽  
High Supersaturation ◽  
Bainitic Structure ◽  
Isothermal Heat Treatments

The effect of isothermal heat treatments (1 hour at 200, 400, 600 and 800°C) on mechanical properties of thermo-mechanically rolled S700MC steel has been investigated by extensive mechanical characterizations. Treatments at 600°C increase yield and tensile strength and decrease impact energy. Below 600°C the steel retains its bainitic structure. Precipitation kinetics simulations indicate that this secondary hardening effect arises from the nucleation of fine (Nb,Ti)C particles, indicating that the bainitic structure is unstable above 600°C due to its high supersaturation with respect to C, Nb and Ti. These results can help to optimize the operating practices for post-weld heat treatments.

Correlation between microstructural evolution during high-pressure torsion and isothermal heat treatment of amorphous Al85Gd8Ni5Co2 alloy

2010 ◽  
Vol 25 (7) ◽  
pp. 1388-1397 ◽  
Author(s):  
Péter Henits ◽  
Ádám Révész ◽  
Erhard Schafler ◽  
Péter J. Szabó ◽  
János L. Lábár ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Thermal Sensitivity ◽  
Heat Treatments ◽  
Isothermal Heat Treatment ◽  
X Ray Diffraction ◽  
Continuous Heat Treatment ◽  
Isothermal Heat Treatments ◽  
Continuous Heat

Al85Gd8Ni5Co2 metallic glass was subjected to partial devitrification by high-pressure torsion, continuous heat treatment, and isothermal annealing. The fully amorphous alloy exhibits a well-defined transition in its first devitrification product during isothermal heat treatments from τm + α-Al phase mixture to primary α-Al by increasing the annealing temperature above 555 K. This thermal sensitivity predestinates the composition to identify the controversial thermal contribution of the plastic deformation in metallic glasses. Thermal stability and structure of the partially devitrified samples were systematically analyzed and compared by calorimetry, x-ray diffraction, and electron microscopy. It seems that the effect of severe deformation cannot be singled out by a simple isothermal heat treatment; i.e., high-pressure torsion acts as a spectrum of heat treatments performed at different annealing temperatures.

scholarly journals Magnetizing lead-free halide double perovskites

2020 ◽  
Vol 6 (45) ◽  
pp. eabb5381
Author(s):  
Weihua Ning ◽  
Jinke Bao ◽  
Yuttapoom Puttisong ◽  
Fabrizo Moro ◽  
Libor Kobera ◽  
...  
Keyword(s):  
High Speed ◽  
Double Perovskite ◽  
Lead Free ◽  
Great Success ◽  
Double Perovskites ◽  
Temperature Dependent ◽  
Magnetic Elements ◽  
Halide Perovskites ◽  
New Generation ◽  
Further Development

Spintronics holds great potential for next-generation high-speed and low–power consumption information technology. Recently, lead halide perovskites (LHPs), which have gained great success in optoelectronics, also show interesting magnetic properties. However, the spin-related properties in LHPs originate from the spin-orbit coupling of Pb, limiting further development of these materials in spintronics. Here, we demonstrate a new generation of halide perovskites, by alloying magnetic elements into optoelectronic double perovskites, which provide rich chemical and structural diversities to host different magnetic elements. In our iron-alloyed double perovskite, Cs2Ag(Bi:Fe)Br6, Fe3+ replaces Bi3+ and forms FeBr6 clusters that homogenously distribute throughout the double perovskite crystals. We observe a strong temperature-dependent magnetic response at temperatures below 30 K, which is tentatively attributed to a weak ferromagnetic or antiferromagnetic response from localized regions. We anticipate that this work will stimulate future efforts in exploring this simple yet efficient approach to develop new spintronic materials based on lead-free double perovskites.

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