Thermal conductivity modelling of alumina/Al functionally graded composites

2014 ◽  
Vol 93 (2) ◽  
pp. 192-200 ◽  
Author(s):  
Christine Pélegris ◽  
Nabil Ferguen ◽  
Willy Leclerc ◽  
Yannick Lorgouilloux ◽  
Stéphane Hocquet ◽  
...  
2020 ◽  
Vol 10 (5) ◽  
pp. 602-609
Author(s):  
Adil H. Awad

Introduction: A new approach for expressing the lattice thermal conductivity of diatomic nanoscale materials is developed. Methods: The lattice thermal conductivity of two samples of GaAs nanobeam at 4-100K is calculated on the basis of monatomic dispersion relation. Phonons are scattered by nanobeam boundaries, point defects and other phonons via normal and Umklapp processes. Methods: A comparative study of the results of the present analysis and those obtained using Callaway formula is performed. We clearly demonstrate the importance of the utilised scattering mechanisms in lattice thermal conductivity by addressing the separate role of the phonon scattering relaxation rate. The formulas derived from the correction term are also presented, and their difference from Callaway model is evident. Furthermore their percentage contribution is sufficiently small to be neglected in calculating lattice thermal conductivity. Conclusion: Our model is successfully used to correlate the predicted lattice thermal conductivity with that of the experimental observation.


2021 ◽  
Vol 865 ◽  
pp. 158976
Author(s):  
Jianshen Wang ◽  
Daniel East ◽  
Evgeny V. Morozov ◽  
Aaron Seeber ◽  
Juan P. Escobedo-Diaz

2005 ◽  
Vol 475-479 ◽  
pp. 1533-1536
Author(s):  
Liu Ding Tang ◽  
Xue Bin Zhang ◽  
Bing Zhe Li

Based on equivalent transformation by means of mathematically rigorous analytics, the stress analysis of heavy cross-sectional, non-homogeneous Functionally Graded Composites (FGCs) has been performed by the layering calculation model in axis-symmetrical mechanics problems. The partially calculated results of the non-homogeneous layered thick-walled metal tube are similar to the design and practice of machine forging moulds manufactured with special welding electrodes developed by the German Capilla Company. The analysis is used complementary to the investigation of the quantitative analysis of thermo-mechanical properties, or the so-called anti-design and the optimization of the graded structure for FGCs.


Materials ◽  
2003 ◽  
Author(s):  
Geun Hyung Kim ◽  
Daniel K. Moeller ◽  
Yuri M. Shkel

A solid composite having locally micro-tailored structure can be produced by curing liquid polymeric suspensions in an electric field. The redistribution effect of the field-induced forces exceeds the effect of centrifugation, presently employed to manufacture functionally graded materials. Moreover, unlike centrifugational sedimentation, one can electrically rearrange the inclusions in desired targeted areas. The applied electric field can be employed to produce a composite having uniformly oriented structure or only modify the material in selected regions. This technology enables polymeric composites to be locally micro-tailored for given design objectives. We discuss electrical and rheological inteactions in liquid suspensions. Relationships between microstructure and mechanical properties of the obtained functionally graded composites are presented.


2008 ◽  
Vol 75 (5) ◽  
Author(s):  
H. M. Yin ◽  
G. H. Paulino ◽  
W. G. Buttlar ◽  
L. Z. Sun

By means of a fundamental solution for a single inhomogeneity embedded in a functionally graded material matrix, a self-consistent model is proposed to investigate the effective thermal conductivity distribution in a functionally graded particulate nanocomposite. The “Kapitza thermal resistance” along the interface between a particle and the matrix is simulated with a perfect interface but a lower thermal conductivity of the particle. The results indicate that the effective thermal conductivity distribution greatly depends on Kapitza thermal resistance, particle size, and degree of material gradient.


2007 ◽  
Vol 353-358 ◽  
pp. 2003-2006 ◽  
Author(s):  
Wei Tan ◽  
Chang Qing Sun ◽  
Chun Fang Xue ◽  
Yao Dai

Method of Lines (MOLs) is introduced to solve 2-Dimension steady temperature field of functionally graded materials (FGMs). The main idea of the method is to semi–discretized the governing equation of thermal transfer problem into a system of ordinary differential equations (ODEs) defined on discrete lines by means of the finite difference method. The temperature field of FGM can be obtained by solving the ODEs with functions of thermal properties. As numerical examples, six kinds of material thermal conductivity functions, i.e. three kinds of polynomial functions, an exponent function, a logarithmic function, and a sine function are selected to simulate spatial thermal conductivity profile in FGMs respectively. The steady-state temperature fields of 2-D thermal transfer problem are analyzed by the MOLs. Numerical results show that different material thermal conductivity function has obvious different effect on the temperature field.


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