High-temperature strength characterization of advanced 9Cr-ODS ferritic steels

2009 ◽  
Vol 510-511 ◽  
pp. 115-120 ◽  
Author(s):  
S. Ukai ◽  
S. Ohtsuka ◽  
T. Kaito ◽  
H. Sakasegawa ◽  
N. Chikata ◽  
...  
Keyword(s):  
High Temperature ◽  
Ferritic Steels ◽  
High Temperature Strength ◽  
Strength Characterization

SYNTHESIS AND CHARACTERIZATION OF Si3N4@Al(OH)3–Y(OH)3 CORE-SHELL COMPOSITE PARTIC3LES

2008 ◽  
Vol 15 (05) ◽  
pp. 581-585 ◽  
Author(s):  
JIE-GUANG SONG ◽  
GANG-CHANG JI ◽  
SHI-BIN LI ◽  
LIAN-MENG ZHANG
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Ceramic Materials ◽  
Composite Particles ◽  
Core Shell ◽  
High Temperature Strength ◽  
Bet Analysis ◽  
Co Precipitation ◽  
Shell Composite

Silicon nitride ( Si 3 N 4) has attracted substantial interest because of its extreme chemical and physical properties, but the sintering densification of Si 3 N 4 is difficult, and it is easily oxidized in the high-temperature air to impact high-temperature strength, which restricts its applied range. In order to decrease the oxidization and improve the strength of Si 3 N 4 at high temperature, the surface of Si 3 N 4 is coated with Al ( OH )3 and Y ( OH )3 to synthesis Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles. Through TEM, XRD, and BET analysis, when pH is about 9, Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles are successfully synthesized by co-precipitation methods. Coating layer is about 200 nm, which is compaction and conformability. Dispersion of coated Si 3 N 4 with Al ( OH )3 and Y ( OH )3 particles are very good. Synthesis of Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite powder will lay the foundation for preparing high-performance YAG/Si 3 N 4 multiphase ceramic materials.

Assessment of ODS Ferritic Alloy for Advanced Nuclear Energy System

2010 ◽  
Author(s):  
Zhangjian Zhou ◽  
Ming Li ◽  
Lu Liao ◽  
Pei He ◽  
Yingli Xu
Keyword(s):  
High Temperature ◽  
Nuclear Energy ◽  
Room Temperature ◽  
Oxide Dispersion Strengthened ◽  
Energy System ◽  
Ferritic Steels ◽  
Ferritic Alloy ◽  
Potential Applications ◽  
Neutron Exposure

Development of cladding materials which can work at high temperature is crucial to realize highly efficient and high-burnup operation of Generation IV nuclear energy systems. Oxide dispersion strengthened (ODS) steels are the most promising class of materials with a potential to be used at elevated temperature under severe corrosion and strong neutron exposure environment. ODS ferritic steels with Cr content of 12–18% were designed and fabricated through the mechanical alloying (MA) route. The characterization of ODS ferritic steels were conducted for evaluation their potential applications for advanced nuclear energy system. Mechanical properties were measured at room temperature and high temperature. High-temperature (700 °C–1000 °C) oxidation resistance were carried out using a muffle. Microstructures of the oxidation layer were observed and compared.

TEM studies of dislocations in deformed Ga1-xInxAs single crystals

1988 ◽  
Vol 46 ◽  
pp. 900-901
Author(s):  
R. S. Rai ◽  
S. Guruswamy ◽  
K. T. Faber ◽  
J. P. Hirth
Keyword(s):  
High Temperature ◽  
Dislocation Density ◽  
Single Crystals ◽  
Dark Field ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Temperature Strength ◽  
Density Reduction ◽  
Transmission Electron

The perfection of GaAs single crystals can be controlled by doping the GaAs with In, at a level of about 5x1019-1x1020/cm3, in single crystals grown by the LEC process. It has been observed that In doping at this level reduces the grown in dislocation density from 104-l05 to ≤ 102/cm2 and results in a large increase in high temperature strength . However, the role of In in dislocation density reduction is not clearly understood. Therefore, a systematic study has been performed with the help of high temperature deformation of In-doped and undoped GaAs single crystals followed by dislocation structural characterization by transmission electron microscopy of the deformed specimens. Here, some results of dislocation studies performed by TEM are descri bed.Samples were examined in a JEOL JEM 200CX transmission electron microscope equipped with a double tilt goniometer stage. The standard g.b criterion was employed for characterization of dislocations. Dark-field weak beam pictures were taken for characterization of partial dislocations and dipoles.

scholarly journals High Temperature Behavior of Al-7Si-0.4Mg Alloy with Er and Zr Additions

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 879
Author(s):  
Elisabetta Gariboldi ◽  
Chiara Confalonieri ◽  
Marco Colombo
Keyword(s):  
High Temperature ◽  
Eutectic Silicon ◽  
A356 Alloy ◽  
Minor Element ◽  
High Temperature Strength ◽  
Creep Tests ◽  
Casting Alloys ◽  
Compression Creep ◽  
Tension And Compression

In recent years, many efforts have been devoted to the development of innovative Al-based casting alloys with improved high temperature strength. Research is often oriented to the investigation of the effects of minor element additions to widely diffused casting alloys. The present study focuses on Al-7Si-0.4Mg (A356) alloy with small additions of Er and Zr. Following previous scientific works on the optimization of heat treatment and on tensile strength, creep tests were carried out at 300 °C under applied stress of 30 MPa, a reference condition for creep characterization of innovative high-temperature Al alloys. The alloys containing both Er and Zr displayed a lower minimum creep strain rate and a longer time to rupture. Fractographic and microstructural analyses on crept and aged specimens were performed to understand the role played by eutectic silicon, by the coarse intermetallics and by α-Al matrix ductility. The creep behavior in tension of the three alloys has been discussed by comparing them to tension and compression creep curves available in the literature for Al-7Si-0.4Mg improved by minor elemental additions.

Coagulation of carbides and its influence on the high-temperature strength of ferritic steels

1985 ◽  
Vol 27 (4) ◽  
pp. 316-319
Author(s):  
V. Fol'dyna ◽  
A. Yakobova ◽  
I. Purmenski ◽  
R. Rzhiman
Keyword(s):  
High Temperature ◽  
Ferritic Steels ◽  
High Temperature Strength

scholarly journals Recent Advances and Developments in Refractory Alloys

1993 ◽  
Vol 322 ◽  
Author(s):  
T.G. Nieh ◽  
J. Wadsworth
Keyword(s):  
High Temperature ◽  
Refractory Metal ◽  
Metal Alloys ◽  
High Temperature Strength ◽  
Refractory Alloys ◽  
Aerospace Applications ◽  
Wide Range ◽  
Recent Developments ◽  
Refractory Metal Alloys

AbstractRefractory metal alloys based on Mo, W, Re, Ta, and Nb (Cb) find applications in a wide range of aerospace applications because of their high melting points and high-temperature strength. In this paper, we present recent progress in the understanding and applications of these alloys. Recent studies to improve the oxidation and mechanical behavior of refractory metal alloys, and particularly Nb alloys, will also be discussed. Some Re structures, for extremely high temperature applications (> 2000°C), made by CVD and P/M processes, are also illustrated. Interesting work on the development of new W alloys (W-HfC-X) and the characterization of some commercial refractory metals, e.g., K-doped W, TZM, and Nb-l%Zr, continues. Finally, recent developments in high temperature composites reinforced with refractory metal filaments, and refractory metal-based intermetallics, e.g., Nb3A1, Nb2Be17, and MoSi2, are briefly described.

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