Fabrication and Characterization of a Functionally Gradient Mo-MoSi2 Composite

1993 ◽  
Vol 322 ◽  
Author(s):  
Gaurav Agarwal ◽  
Wen-Yi Lin ◽  
Robert. F. Speyer
Keyword(s):  
Gradient Material ◽  
Reaction Products ◽  
Reducing Atmosphere ◽  
Functionally Gradient ◽  
Cyclic Heat ◽  
Cte Mismatch ◽  
Fabrication And Characterization ◽  
Mosi2 Composite ◽  
Functionally Gradient Composite

AbstractFor the application of immersed combustion-radiant tubes in glass melters, a Mo-MoSi2 functionally gradient composite was developed. A gradient profile mixture with varying amounts of powders of these two compounds was hot pressed at 1650°C and 17.4 MPa. Mo5Si3, and Mo3Si reaction products were detected by XRD in the hot pressed composite. Limited cracking was apparent in regions where pure Mo regions applied tensile stresses to regions rich in Mo3Si product. Cyclic heat treatments in a reducing atmosphere showed no signs of further CTE mismatch induced cracking, but did indicate a propensity to creep under load at ∼ 1400°C. A functionally gradient material with MoSi2 on all exterior surfaces showed excellent oxidation protection to the Mo center.

Fabrication and Characterization of Aluminum (6061)-Boron-Carbide Functionally Gradient Material

2010 ◽  
Vol 25 (7) ◽  
pp. 572-576 ◽  
Author(s):  
A. G. Rao ◽  
M. Mohape ◽  
V. A. Katkar ◽  
D. S. Gowtam ◽  
V. P. Deshmukh ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Gradient Material ◽  
Functionally Gradient Material ◽  
Functionally Gradient ◽  
Fabrication And Characterization

Wear Analysis of Functionally Gradient Composite Materials by FE Modelling of Microhardness Measurements and Wear Tests

2007 ◽  
Vol 537-538 ◽  
pp. 519-526
Author(s):  
David Felhös ◽  
Karoly Váradi ◽  
Klaus Friedrich
Keyword(s):  
Wear Behavior ◽  
Gradient Material ◽  
Material Structure ◽  
Fe Modelling ◽  
Sem Images ◽  
Wear Analysis ◽  
Functionally Gradient ◽  
Sic Reinforcement ◽  
Wear Tests ◽  
Functionally Gradient Composite

Rollers of three different material structures were examined: rollers consisting of pure EP resin; homogeneous EP/SiC composite rollers containing 5 vol.% SiC; and EP/SiC composite rollers with functionally gradient (FG) material structure. Wear tests were performed on the rollers. The wear tests showed that rollers of gradient structure are the most wear-resistant of all. Microhardness measurements were performed on the materials of the three different rollers. SEM images were made of the surface of wear traces. In order to get to know better the effect of SiC reinforcement particles on the wear mechanism, microhardness measurements were simulated by 3D FE micro-models. The SEM images and the FE models were used to explain the excellent wear behavior of the tread of rollers with gradient material distribution.

Preparation and Characterization of Multilayered Mullite/Mo Functionally Gradient Materials

2008 ◽  
Vol 368-372 ◽  
pp. 1866-1868
Author(s):  
Shu Heng Chen ◽  
Lin Jiang Wang ◽  
Xiang Li Xie ◽  
Ye Zhang
Keyword(s):  
Relative Density ◽  
Thermal Shock ◽  
Gradient Material ◽  
Thermal Shock Test ◽  
Composition Distribution ◽  
Shock Test ◽  
Gradient Materials ◽  
Functionally Gradient ◽  
New Phase

Multilayered mullite/Mo cermet functionally gradient material (FGM) was fabricated through a powder stacking process and sintering in vacuum up to 1500°C. The composition distribution, microstructure and microhardness of the FGM were analyzed. The results indicated that the mullite/Mo FGM was well densified with composite graded distribution and there was no new phase appeared. The microhardness of the FGM increase from 467HV to 1543HV, the density from 2.919 to 7.106 g/cm3 as the content of mullite increase from 20% to 80%. The relative density exceeded 90% as the content of mullite reached 80%. Thermal shock test showed that the cracks passed through the joint without deflection.

Micro-observation and characterization of bonding between bone and HA-glass-titanium functionally gradient composite

Biomaterials ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 225-230 ◽  
Author(s):  
S. Maruno ◽  
H. Itoh ◽  
S. Ban ◽  
H. Iwata ◽  
T. Isikawa
Keyword(s):  
Functionally Gradient ◽  
Functionally Gradient Composite

Fabrication and characterization of SiCw/MoSi2 composite from COSHSed powder

2007 ◽  
Vol 42 (14) ◽  
pp. 5795-5798 ◽  
Author(s):  
Jianguang Xu ◽  
Baolin Zhang ◽  
Guojian Jiang ◽  
Wenlan Li ◽  
Hanrui Zhuang
Keyword(s):  
Fabrication And Characterization ◽  
Mosi2 Composite

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

Fabrication and Characterization of Polyoxometalate based Nano-hybrids: Evaluation of their role in Biological Activity

2019 ◽  
Vol 35 (4) ◽  
pp. 475-484
Author(s):  
SHIVA ARUN ◽  
◽  
PRABHA BHARTIYA ◽  
AMREEN NAZ ◽  
SUDHEER RAI ◽  
...  
Keyword(s):  
Biological Activity ◽  
Fabrication And Characterization

Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN
Keyword(s):  
Mass Transfer ◽  
Molecular Mass ◽  
Initial Phase ◽  
Degradation Products ◽  
Kraft Pulping ◽  
Reaction Products ◽  
Cooking Temperature ◽  
Molecular Masses ◽  
Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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