Combustion Synthesis of MoSi2 and MoSi2-Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
K. Monroe ◽  
S. Govindarajan ◽  
J.J. Moore ◽  
B. Mishra ◽  
D.L. Olson ◽  
...  
Keyword(s):  
Composite Material ◽  
Thermal Expansion ◽  
High Temperature ◽  
Combustion Synthesis ◽  
Functionally Graded ◽  
Potential Candidate ◽  
Structural Components ◽  
Graded Materials ◽  
Material Systems ◽  
Selection Of

AbstractMosi2 and Mosi2-composites are potential candidate materials for both high-temperature coatings and structural components. The application of combustion synthesis and hot pressing in the production of dense Mosi2 and Mosi2- composites, i.e., Mosi2-SiC, Mosi2 -Mo, is currently being studied. Selection of compositions was based on oxidation resistance, thermal expansion, thermodynamic stability, and compatibility. Functionally-graded materials (FGM's) of these composite material systems are also currently being studied.

Hot Dynamic Densification of Materials by Utilizing Underwater Shock Wave

2012 ◽  
Vol 706-709 ◽  
pp. 793-798 ◽  
Author(s):  
Ryuichi Tomoshige ◽  
Seiichiro Ii ◽  
Masahiro Fujita ◽  
Akira Chiba
Keyword(s):  
High Temperature ◽  
Ceramic Composites ◽  
Functionally Graded ◽  
Underwater Shock Wave ◽  
Graded Materials ◽  
High Temperature Synthesis ◽  
Two Phases ◽  
Tini Phase ◽  
Short Time ◽  
Dynamic Densification

Hot dynamic densification method was developed by combining self-propagating high temperature synthesis (SHS) with explosively shock powder compaction technique. This method is extremely short time processing. The main purpose in this study is to perform from synthesis to densification of TiB2-TiN system high temperature ceramic composites and TiB2-TiNi-Cu system functionally graded materials (FGMs) in one step. In TiN-TiB2 ceramic composites, they showed up to 95% of relative density. It was appeared by TEM observations that both the two phases joined tightly each other. The FGMs also were produced by the same technique. They indicated no interlayer exfoliation and no macro cracks after thermal shock tests from 973 K to room temperature. It was shown that thermoelastic property of intermetallic TiNi phase as intermediate layer between ceramics and metal layers operated effectively.

Self-propagating high-temperature synthesis of functionally graded materials as thermal protection systems for high-temperature applications

2003 ◽  
Vol 18 (2) ◽  
pp. 448-455 ◽  
Author(s):  
N. Bertolino ◽  
M. Monagheddu ◽  
A. Tacca ◽  
P. Giuliani ◽  
C. Zanotti ◽  
...  
Keyword(s):  
High Temperature ◽  
Functionally Graded Materials ◽  
Thermal Protection ◽  
Functionally Graded ◽  
Temperature Synthesis ◽  
Thermal Tests ◽  
Graded Materials ◽  
Thermal Barriers ◽  
High Temperature Synthesis ◽  
Spatial Composition

Self-propagating high-temperature synthesis was used to prepare boride-based functionally graded materials (FGMs) as thermal barriers for space re-entry vehicles. FGMs are characterized by inhomogeneous spatial composition, resulting in different spatial characteristics. In this work, the FGMs were composed of a ceramic [i.e., MB2 (M = Ti, Zr, Hf)] and a metallic (i.e., NiAl) side, joined together by composite layers of graded stoichiometries of the two components. Thus, in the same material, the boride end gives thermal insulation, while the intermetallic end offers an easy junction to the structure of the space aircraft. The prepared FGMs showed good adhesion between the layers and global compactness after preparation and thermal tests. The microhardness along the samples was measured, and their insulating capabilities were evaluated.

Analytical Solution of Thermal Stresses in a Functionally Graded Solid Cylinder within Parabolic Continuous Grading

2013 ◽  
Vol 307 ◽  
pp. 364-367 ◽  
Author(s):  
Ali Ozturk ◽  
Müfit Gülgeç
Keyword(s):  
Thermal Expansion ◽  
Analytical Solution ◽  
Material Properties ◽  
Thermal Conduction ◽  
Thermal Stresses ◽  
Elasticity Modulus ◽  
Functionally Graded ◽  
Solid Cylinder ◽  
Graded Materials ◽  
Parabolic Form

This paper presents analytical solutions of the thermal stresses in a functionally graded solid cylinder with fixed ends in elastic region. These thermal stresses are due to the uniform heat generation inside the cylinder. Material properties of the functionally graded (FG) cylinder vary radially according to a parabolic form. The material properties are assumed to be independent of the temperature which are yield strength, elasticity modulus, thermal conduction coefficient, thermal expansion coefficient and Poisson’s ratio. The solutions for the thermal stresses are valid for both homogeneous and functionally graded materials.

Centrifugally-assisted combustion synthesis of functionally-graded materials

1997 ◽  
Vol 36 (3) ◽  
pp. 331-334 ◽  
Author(s):  
W. Lai ◽  
Z.A. Munir ◽  
B.J. McCoy ◽  
S.H. Risbud
Keyword(s):  
Combustion Synthesis ◽  
Functionally Graded Materials ◽  
Functionally Graded ◽  
Graded Materials

Thermal stress analysis of functionally graded solid and hollow thick-walled structures with heat generation

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mehmet Eker ◽  
Durmuş Yarımpabuç ◽  
Kerimcan Çelebi
Keyword(s):  
Heat Generation ◽  
Internal Heat ◽  
Functionally Graded ◽  
Graded Materials ◽  
Content Type ◽  
Chebyshev Method ◽  
External Conditions ◽  
Cylinders And Spheres ◽  
Solid Bodies ◽  
Selection Of

Purpose This paper aims to present thermal and mechanical stresses in solid and hollow thick-walled cylinders and spheres made of functionally graded materials (FGMs) under the effect of heat generation. Design/methodology/approach Constant internal temperature and convective external conditions in hollow bodies along with internal heat generation with a combination of outer convective conditions in solid bodies are investigated individually. The effect of the heat convection coefficient on solid bodies is additionally discussed. The variation of the FGM properties in the radial direction is adapted to the Mori–Tanaka homogenization schemes, which produces irregular and two-point linear boundary value problems that are numerically solved by the pseudospectral Chebyshev method. Findings It has been shown that the selection of the mixtures of FGMs has to be made correctly to keep the thermal and mechanical loads acting on objects at low levels. Originality/value In this study, both solid and hollow functionally graded cylinders and spheres for different boundary conditions that are as their engineering applications are examined with the proposed method. The results have demonstrated that the pseudospectral Chebyshev method has high accuracy, low calculation costs and ease of application and can be easily adapted to such engineering problems.

Correlation of Measured Thermal Conductivity to a Functionally Graded Material's Microstructure

1997 ◽  
Vol 3 (S2) ◽  
pp. 789-790
Author(s):  
John Phelps ◽  
Andrew Slifka ◽  
James Filla
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Thermal Loading ◽  
Extreme Environments ◽  
Conductivity Measurement ◽  
Functionally Graded ◽  
Stabilized Zirconia ◽  
Graded Materials ◽  
Graded Coating ◽  
Machined Parts

Functionally Graded Materials (FGMs) are used in a number of applications as a protective barrier to extreme environments. One such application of FGMs is to protect metal parts from high temperature environments. FGM coatings are plasma spray deposited onto surfaces of both simple and complex machined parts. Knowing the thermal conductivity of the FGM coating allows engineers to effectively develop high temperature designs with accurate estimates of heat transfer and thermal loading.In this study, a FGM made by Caterpillar, USA, was measured with our steady state thermal conductivity measurement apparatus. The sample measured is a 10 layer graded coating using a Metro* 461 bond coan4 to a Metco* 205 ceria-yittria stabilized zirconia, with a Ni-Co-Cr-Al-Y metal grading. Figure 1 shows a plot of the thermal conductivity (W/m*K) as a function of temperature (K) for this material. The sudden drop in thermal conductivity at approximately 1073K was totally unexpected

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