Microstructure and mechanical properties of spark plasma sintered Al2O3-SiC-CNTs hybrid nanocomposites

On the thermal conductivity of spark plasma sintered alumina hybrid nanocomposites: Estimation modeling and experimental validation

“…In addition, monolithic alumina, as a reference sample, was sintered at the same conditions. More details on the consolidation process can be found elsewhere [5].To further understand the effect of average alumina crystallite size of its thermal conductivity, additional monolithic alumina samples were sintered under different sets of sintering conditions. For these monolithic Alumina samples, three different sintering temperatures i.e.…”

“…The increase in SiC content to 10 wt.% led to a further decrease in the relative density to reach 95.43 and 95.40 % for Al 2 O 3 -10SiC-1CNT and Al 2 O 3 -10SiC-2CNT, respectively. This reduction of the density due to the incorporation of SiC and CNTs in alumina can be attributed to the reduced ability of the composite to plastically deform and the reduced grain boundary diffusion due to the pinning effect of the inclusions at the grain boundaries [4,5].…”

“…The fitted model for the thermal conductivity of polycrystalline alumina is given by the equation (11). The single crystal thermal conductivity of alumina was determined to be 34.55 W/m•K and the thermal resistance of the crystallite interfaces was estimated as The generalized effective medium theory model of Siddiqui and Arif, shown in equations (1)(2)(3)(4)(5)(6)(7)(8)(9), was used to estimate the thermal conductivity of the spark plasma sintered alumina matrix composites with SiC and CNT hybrid inclusions. The results are listed in Tab.…”

“…The brittleness of monolithic ceramics had limited their use in many applications [1]. Fortunately, removal of this limitation was made possible through the development of composites [2], nanocomposites [3], and hybrid nanocomposites [4,5]. Hybrid ceramic nanocomposites are advanced ceramic materials obtained by reinforcing a ceramic matrix with two nano-reinforcements that have different morphologies and/or attributes.…”

“…Reinforcing alumina with two nanoscale phases has proven to be an efficient way for the improvement of its properties and performance. Analysis of literature shows that the majority of research work published on alumina hybrid nanocomposites has been devoted to the characterization of the microstructure and the evaluation of mechanical properties [5][6][7]. Although, thermal properties in general and thermal conductivity in particular, are among the most important factors used in materials selection for engineering design, published work on the thermal conductivity of alumina hybrid nanocomposites produced by spark plasma sintering is very scarce [9].…”