Study on Morph-Genetic Materials Derived from Natural Structure

2005 ◽  
Vol 502 ◽  
pp. 373-378
Author(s):  
Di Zhang ◽  
Tong Xiang Fan ◽  
Bing He Sun ◽  
Tian Chi Wang ◽  
Xian Qing Xie ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Molten Metal ◽  
Advanced Materials ◽  
Materials Processing ◽  
Interpenetrating Networks ◽  
Natural Structure ◽  
Novel Technology ◽  
Use Values ◽  
Natural Plants

Synthesis of morph-genetic materials derived from biological structures by rapid, high temperature conversion represents a novel technology of advanced materials processing. The resulting morph-genetic materials exhibit unique macro- and microscopic cellular morphologies. In addition, based on the porous character of some natural plants, there is a further possibility of compounding the resulting morph-genetic materials with molten metal or polymer to produce morph-genetic composites with interpenetrating networks. Thus, the morph-genetic materials will be endowed with new use values, such as good mechanical properties, and friction behaviors, etc.

Recent progress in the assessment of irradiation effects for in-vessel fusion materials: Tungsten and copper alloys

2021 ◽  
Author(s):  
Dmitry Terentyev ◽  
Michael Rieth ◽  
Gerald Pintsuk ◽  
Johann Riesch ◽  
Alexander Von Muller ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Copper Alloys ◽  
Fusion Energy ◽  
Advanced Materials ◽  
High Temperature Strength ◽  
Present Contribution ◽  
Operational Conditions ◽  
Operation Temperature ◽  
Plasma Facing Components

Abstract The present contribution highlights results of the recent irradiation campaigns applied to screen mechanical properties of advanced tungsten and copper-based materials – main candidates for the application in the plasma-facing components (PFC) in the European DEMO, which has also been presented at 28th IAEA Fusion Energy Conference. The main challenges in the formulated irradiation programme were linked to: (I) assessment of the ductile-to-brittle transition temperature (DBTT) of newly developed tungsten-based materials; (ii) investigation of an industrial pure tungsten grade under high temperature irradiation, reflecting operational conditions in the high flux divertor region; (iii) assessment of the high temperature strength of CuCrZr-based alloys and composites developed to enable the extension of the operational window for the heat sink materials. The development and choice of the advanced materials is driven naturally by the need to extend the operation temperature/fluence window thereby enlarging the design space for PFCs. The obtained results helped identifying the prospective tungsten and copper-based material grades as well as yielded a number of unexpected results pointing at severe degradation of the mechanical properties due to the irradiation. The results are discussed along with the highlights of the microstructural examination. An outlook for near future investigations involving in-depth post-irradiation examination and further irradiation campaigns is provided.

Supercritical Fluid Applications in Advanced Materials Processing

1988 ◽  
Vol 121 ◽  
Author(s):  
Richard A. Wagner ◽  
Val J. Krukonis ◽  
Michael P. Coffey
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Physical Properties ◽  
Oxidation Resistance ◽  
Supercritical Fluid ◽  
Supercritical Fluids ◽  
Char Yield ◽  
Advanced Materials ◽  
Materials Processing ◽  
Carbon Composites

ABSTRACTThe feasibility of using supercritical fluids to impregnate carbon/carbon composites with a ceramic precursor was successfully demonstrated. Improvements in mechanical properties and oxidation resistance were correlated with the distribution of silicon within the microstructure of the composites. In addition, supercritical fluids were also used to fractionate silicon carbide precursors and thereby control the physical properties and char yield.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

AEM of reaction-bonded SiC

1992 ◽  
Vol 50 (1) ◽  
pp. 344-345
Author(s):  
K Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
High Temperature ◽  
Epitaxial Growth ◽  
Liquid Silicon ◽  
Structural Ceramic ◽  
Few Data

Research on reaction-bonded SiC (RBSiC) is aimed at developing a reliable structural ceramic with improved mechanical properties. The starting materials for RBSiC were Si,C and α-SiC powder. The formation of the complex microstructure of RBSiC involves (i) solution of carbon in liquid silicon, (ii) nucleation and epitaxial growth of secondary β-SiC on the original α-SiC grains followed by (iii) β>α-SiC phase transformation of newly formed SiC. Due to their coherent nature, epitaxial SiC/SiC interfaces are considered to be segregation-free and “strong” with respect to their effect on the mechanical properties of RBSiC. But the “weak” Si/SiC interface limits its use in high temperature situations. However, few data exist on the structure and chemistry of these interfaces. Microanalytical results obtained by parallel EELS and HREM imaging are reported here.

ALUMINUM 220

Alloy Digest ◽  
1962 ◽  
Vol 11 (3) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Heat Treating ◽  
Casting Alloy ◽  
Aluminum Casting ◽  
Aluminum Casting Alloy ◽  
Temperature Performance ◽  
Aluminum Company

Abstract ALUMINUM 220 is a 10% magnesium-aluminum casting alloy having the highest combination of mechanical properties, corrosion resistance and machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-112. Producer or source: Aluminum Company of America.

ALUMINUM 2011

Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Temperature Performance ◽  
Screw Machine ◽  
Aluminum Copper Alloy

Abstract ALUMINUM 2011 is an age-hardenable aluminum-copper alloy to which lead and bismuth are added to make it a free-machining alloy. It has good mechanical properties and was designed primarily for the manufacture of screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-32. Producer or source: Various aluminum companies. Originally published October 1955, revised December 1978.

Sign in / Sign up

Export Citation Format

Share Document