Thermal conductivities, electrical resistivities, and thermal expansion of titanium carbonitrides and oxycarbides

1978 ◽  
Vol 17 (8) ◽  
pp. 613-616 ◽  
Author(s):  
N. A. Ivanov ◽  
L. P. Andreeva ◽  
P. V. Gel'd
Keyword(s):  
Thermal Expansion ◽  
Titanium Carbonitrides ◽  
Electrical Resistivities ◽  
Thermal Conductivities

Temperature dependence of the electrical resistivities, thermal conductivities, and coefficients of thermal expansion of P/M carbon and low-alloy steels

1983 ◽  
Vol 22 (9) ◽  
pp. 717-720
Author(s):  
I. D. Radomysel'skii ◽  
V. N. Klevtsov ◽  
I. D. Martyukhin ◽  
S. G. Napara-Volgina ◽  
A. Ya. Kuchma ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Low Alloy Steels ◽  
Electrical Resistivities ◽  
Alloy Steels ◽  
Thermal Conductivities

Thermal Expansion and Isotopic Composition Effects on Lattice Thermal Conductivities of Crystalline Silicon

2006 ◽  
Author(s):  
Yunfei Chen ◽  
Guodong Wang ◽  
Deyu Li ◽  
Jennifer R. Lukes
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Md Simulation ◽  
Lattice Thermal Conductivity ◽  
Mass Difference ◽  
Dynamics Simulation ◽  
Temperature Range ◽  
Simulation Results ◽  
Callaway Model ◽  
Thermal Conductivities

Equilibrium molecular dynamics simulation is used to calculate lattice thermal conductivities of crystal silicon in the temperature range from 400K to 1600K. Simulation results confirmed that thermal expansion, which resulted in the increase of the lattice parameter, caused the decrease of the lattice thermal conductivity. The simulated results proved that thermal expansion imposed another type resistance on phonon transport in crystal materials. Isotopic and vacancy effects on lattice thermal conductivity are also investigated and compared with the prediction from the modified Debye Callaway model. It is demonstrated in the MD simulation results that the isotopic effect on lattice thermal conductivity is little in the temperature range from 400K to 1600K for isotopic concentration below 1%, which implies the isotopic scattering on phonon due to mass difference can be neglected over the room temperature. The remove of atoms from the crystal matrix caused mass difference and elastic strain between the void and the neighbor atoms, which resulted in vacancy scattering on phonons. Simulation results demonstrated this mechanism is stronger than that caused by isotopic scattering on phonons due to mass difference. A good agreement is obtained between the MD simulation results of silicon crystal with vacancy defects and the data predicted from the modified Debye Callaway model. This conclusion is helpful to demonstrate the validity of Klemens' Rayleigh model for impurity scattering on phonons.

Investigation of Strontium-Niobium Oxides for Application to Thermal Barrier Coatings

2006 ◽  
Vol 317-318 ◽  
pp. 517-520 ◽  
Author(s):  
Masato Shida ◽  
Katsunori Akiyama ◽  
Ichiro Nagano ◽  
Yuichiro Murakami ◽  
Satoshi Ohta
Keyword(s):  
Thermal Expansion ◽  
Thermal Barrier Coatings ◽  
Solid Solutions ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Niobium Oxides ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Thermal Conductivities

We have been trying to find new oxide compounds with large thermal expansion coefficients and low thermal conductivities by means of a material calculation technique. Among thousands of compounds in the databases, we found that there were some materials with low thermal conductivities and large thermal expansion coefficients in the group of strontium-niobium oxides. For example, Sr4Nb2O9 has a thermal expansion coefficient of 14.510-6 / and thermal conductivity of 1.0 W/mK, although a slight amount of other phases appear during long-term annealing. These thermal properties are better than those of yttria-stabilized zirconia, which is the standard material for thermal barrier coatings. To prevent the precipitation of other phases, we prepared the solid solutions, Sr4Nb2-xMxO9. In this study, the thermal conductivities and thermal expansion coefficients of these solid solutions were measured, and their thermal stabilities were evaluated by long-term annealing.

High Thermal Conductivity Graphite Copper Composites with Diamond Coatings for Thermal Management Packaging Applications

1995 ◽  
Vol 390 ◽  
Author(s):  
Chris H. Stoessel ◽  
C. Pan ◽  
J. C. Withers ◽  
D. Wallace ◽  
R. O. Loutfy
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Management ◽  
Heat Sinks ◽  
High Thermal Conductivity ◽  
Graphite Fiber ◽  
Fiber Reinforced ◽  
Cathode Sputtering ◽  
Large Expansion ◽  
Thermal Conductivities

ABSTRACTHigh thermal conductivity heat sinks for thermal management in electronic packaging is enabling to a variety of advanced electronic applications. Heat sinks in industrial semiconductor application have thermal conductivities generally less than 180 W/mK, and frequently have large expansion mismatch with chips such as silicon and gallium arsenide. A unique technology of producing graphite fiber reinforced copper (Cf/Cu) composite has been developed that produced thermal conductivities up to 454 W/mK utilizing a K=640 W/mK fiber reinforcement (with a potential for 800 W/mK when utilizing a K = 1100 W/mK P130 fiber) and thermal expansion that can be matched to chip materials. The process consists of utilizing a hollow cathode sputtering process to deposit a bonding layer followed by copper on spread graphite fibers, which are then consolidated into composites with architectures to achieve desired thermal conductivity and thermal expansion. The copper thickness determines graphite fiber loading up to 80 %. In heat sink applications, where the electrical conductivity of the graphite fiber reinforced copper composite is a problem, processing has been developed for applying electrically insulating diamond film, which has high thermal conductivity and acts as a heat spreader.

Microstructure and Thermal Properties of Diamond-Al Composite Fabricated by Pressureless Metal Infiltration

2010 ◽  
Vol 150-151 ◽  
pp. 1110-1118 ◽  
Author(s):  
Yan Cui ◽  
Song Bo Xu ◽  
Lei Zhang ◽  
Shun Guo
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Thermal Management ◽  
Expansion Coefficient ◽  
Metallic Matrix ◽  
Interfacial Bonding ◽  
Interfacial Structure ◽  
Diamond Particles ◽  
Metal Infiltration ◽  
Thermal Conductivities

For obtaining materials with high thermal conductivities and suitable thermal expansion coefficient for thermal management applications, diamond/Al composites were fabricated by the low-cost pressureless metal infiltration. The resulting composites exhibited thermal conductivities as high as 518.7 W/m•K and thermal expansion coefficient as low as 4.61×10-6/K friendly matching with semiconductors materials like Si or GaAs. The diamond particles were not only well embedded, but also uniformly distributed in the metallic matrix along with SEM observations of the composites. Fractograph of the composites illustrated that aluminum matrix fracture was the dominant fracture mechanism and the stepped breakage of diamond particles indicated strong interfacial bonding between diamond and the Al matrix. The Si skeleton with coralline morphology in the interface between diamond and the matrix were found to play a role of bridge in the interfacial structure and result in distinctive interfacial bonding. Also a little content of Al4C3 were realized to have positive effect on the improved thermal conductivities for promoting interfacial bonding between aluminum and diamond. In addition, the excellent mechanical behavior of the composite was illustrated. The results shows a superior Young’s modulus of 286 GPa compared with traditional thermal management materials and relatively high bending strength of 306MPa.

Ternary Skutterudites: Anion Ordering and Thermoelectric Properties

2007 ◽  
Vol 1044 ◽  
Author(s):  
Paz Vaqueiro ◽  
Gerard G. Sobany
Keyword(s):  
Seebeck Coefficient ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Electrical Transport ◽  
Powder Diffraction Data ◽  
Electrical Transport Properties ◽  
Electrical Resistivities ◽  
Thermal Conductivities

AbstractThe ternary skutterudites AB1.5Q1.5 (A = Co, Rh, Ir, B =Ge, Sn and Q = S, Te) have been synthesized and structurally characterised. Powder diffraction data are consistent with the presence of anion ordering, which results in a lowering of the symmetry from cubic to rhombohedral. The ordered skutterudite structure contains rhomboidal four-membered B2Q2 rings, instead of the homonuclear rectangular rings found in binary skutterudites. The electrical transport properties of the AB1.5Q1.5 phases are consistent with semiconducting behaviour, and large values of the Seebeck coefficient have been observed for several of these materials. While their large electrical resistivities might make these materials unsuitable for thermoelectric applications unless significant improvements can be achieved by doping, these materials also exhibit significantly lower thermal conductivities than their binary counterparts.

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