The Fabrication of High Silicon-Aluminum Composites and the Thermal Conductivity

2014 ◽  
Vol 941-944 ◽  
pp. 288-293
Author(s):  
Xing Yu Chen ◽  
Yan Xia Li ◽  
Jun You Liu
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Resistance ◽  
Diffusion Zone ◽  
Aluminum Composites ◽  
Interface Thermal Resistance ◽  
Innovative Method ◽  
Si Content ◽  
Al Matrix ◽  
Silicon Particles

Silicon-aluminum composites with Si content of 42-70 wt. % were fabricated by an innovative method of liquid-solid separation. The microstructures and thermal conductivity analyzing and predicting by the Maxwell and Hasselman-Johnson models were executed. The results show that silicon particles in composites are near globular with dull angular and surrounded by the continuous Al matrix, and the interface among them is composed of element diffusion zone. The conductivities of four composites are beyond 120 W. m-1 .K-1 at 25°C but reduce with Si content adding. The coarse particle size is beneficial to the higher conductivity. The interface thermal resistance of composites obtained by theoretical calculation is 16.0×107 W.m-2.K-1, and using it the H-J model can be employed to predict the conductivity.

Characterisation of high thermal conductivity thin-film substrate systems and their interface thermal resistance

2018 ◽  
Vol 334 ◽  
pp. 233-242 ◽  
Author(s):  
Alireza Moridi ◽  
Liangchi Zhang ◽  
Weidong Liu ◽  
Steven Duvall ◽  
Andrew Brawley ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Thermal Resistance ◽  
High Thermal Conductivity ◽  
Interface Thermal Resistance ◽  
Film Substrate

Thermal Resistance of Bond-Lines Formed With Composite Thermal Interface Materials

2005 ◽  
Author(s):  
Gary Lehmann ◽  
Hao Zhang ◽  
Arun Gowda ◽  
David Esler
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Resistance ◽  
Bond Line ◽  
Surface Conductance ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Bond Line Thickness ◽  
Matrix Surface ◽  
Interface Materials

Measurements and modeling of the thermal resistance of thin (< 100 microns) bond-lines are reported for composite thermal interface materials (TIMs). The composite TIMs consist of alumina particles dispersed in a polymer matrix to form six different adhesive materials. These model TIMs have a common matrix material and are distinguished by their particle size distributions. Bond-lines are formed in a three-layer assembly consisting of a substrate-TIM-substrate structure. The thermal resistance of the bond-line is measured, as a function of bond-line thickness, using the laser flash-technique. A linear variation of resistance with bond-line thickness is observed; Rbl = β · Lbl + Ro. A model is presented that predicts the effective thermal conductivity of the composite as a function of the particle and matrix conductivity, the particle-matrix surface conductance, the particle volume fraction and the particle size distribution. Specifically a method is introduced to account for a broad, continuous size distribution. A particle-matrix surface conductance value of ∼10W/mm2K is found to give good agreement between the measured and predicted effective thermal conductivity values of the composite TIMs.

Thermal Transport through Solid-Solid Interface with an Interlayer

2011 ◽  
Vol 483 ◽  
pp. 750-754
Author(s):  
Ya Dong Liu ◽  
Ke Dong Bi ◽  
Yun Fei Chen ◽  
Min Hua Chen
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Thermal Resistance ◽  
Thermal Transport ◽  
System Size ◽  
Simulation System ◽  
Nonequilibrium Molecular Dynamics ◽  
Solid Interface ◽  
Interface Thermal Resistance ◽  
System Temperature

Nonequilibrium molecular dynamics (NEMD) approach is developed to investigate the thermal transport across a solid-solid interface between two different materials with an interlayer around it. The effects of system size and the interlayer material’s properties on the interface thermal resistance are considered in our model. The NEMD simulations show that the addition of an interlayer between two highly dissimilar lattices depresses the interface thermal resistance effectively. Meanwhile, the effective thermal conductivity along the direction of heat flux is enhanced with the increasing system temperature. Moreover, the interface thermal resistance after including an interlayer does not depend strongly on the simulation system size.

Study of Effective Thermal Conductivity of Glazed Hollow Bead Concrete

2016 ◽  
Vol 851 ◽  
pp. 823-828
Author(s):  
Bing Zhang ◽  
Zhong Qing Cheng
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Thermal Conductivity Coefficient ◽  
Interface Thermal Resistance

Based on analyzing the mechanism of thermal conductivity of glazed hollow bead concrete, this paper divides the channels of thermal conductivity in concrete, constructs the model of thermal conductivity coefficient based on the Theory of Minimum Thermal Resistance, and confirms the model by using the data of other related literatures and the data of our own experiment. The consequence indicates that this model can calculate the thermal conductivity coefficient under arid state exactly. In order to improve the accuracy of this model, we should take the shape of framework, the interface thermal resistance between concrete and framework into consideration

Two-Step Raman Method for Interface Thermal Resistance and In-Plane Thermal Conductivity Characterization of Graphene Interface Materials

2016 ◽  
Author(s):  
Man Li ◽  
Yanan Yue
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Graphene Film ◽  
Phonon Transport ◽  
Interfacial Thermal Resistance ◽  
Transfer Model ◽  
Interface Thermal Resistance ◽  
Graphene Interface ◽  
Interface Materials

The negative influence of substrate on in-plane phonon transport in graphene has been revealed by intensive research, whereas the interaction between phonons couplings across graphene/substrate interface and within graphene is still needed to figure out. In this work, we put forward a two-step Raman method to accomplish interface thermal resistance characterization of graphene/SiO2 and in-plane thermal conductivity measurement of supported graphene by SiO2. In order to calculate the interfacial thermal resistance, the temperature difference between graphene and its substrate was probed using Raman thermometry after the graphene film was uniformly electrically heated. Combing the ITR and the temperature response of graphene to laser heating, the thermal conductivity was computed using the fin heat transfer model. Our results shows that the thermal resistance of free graphene/SiO2 is enormous and the thermal conductivity of the supported graphene is significantly suppressed. The phonons scattering and leakage at the interface are mainly responsible for the reduction of thermal conductivity of graphene on substrate. The morphology change of graphene caused by heating mainly determines the huge interfacial thermal resistance and partly contributes to the suppression of thermal conductivity of graphene. This thermal characterization approach simultaneously realizes the non-contact and non-destructive measurement of interfacial thermal resistance and thermal conductivity of graphene interface materials.

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