Heat sinks are commonly used for cooling electronic devices and high-power electrical systems. The ever-increasing performance of electronic systems together with miniaturization calls for better heat dissipation. Therefore, the heat sink materials should not only have high thermal conductivities, low densities, and cost, but also have coefficients of thermal expansion matching to those of semiconductor chips and ceramic substrates. As traditional materials fail to meet these requirements, new composite materials have been developed with a major focus on metal matrix composites (MMCs). MMCs can be tailored to obtain the desired combination of properties by selecting proper metallic matrix and optimizing the size and type, volume fraction, and distribution pattern of the reinforcements. Hence, the current review comprehensively summarizes different studies on enhancing the thermal performance of metallic matrices using several types of reinforcements and their combinations to produce composites. Special attention is paid to the types of commonly used metallic matrices and reinforcements, processing techniques adopted, and the effects of each of these reinforcements (and their combinations) on the thermal properties of the developed composite. Focus is also placed on highlighting the significance of interfacial bonding in achieving optimum thermal performance and the techniques to improve interfacial bonding.

The low hardness and strength of aluminum, which limits its use in many industrial applications, could be increased through the addition of nanoparticles. However, the appropriate processing method and parameters should be carefully selected in order to achieve the desired improvement in properties. In this work, aluminum was reinforced with low weight fraction (1 wt.%) of SiC nanoparticles and consolidated through spark plasma sintering. The effect of processing parameters on the densification, microstructure, and properties of the processed material was investigated. Field Emission Scanning Electron Microscope (FE-SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS) facility was used to characterize the microstructure and analyze the reinforcement’s distribution in sintered samples. Phases present were characterized through X-ray diffraction (XRD). A densimeter and a digital microhardness tester were used to measure the density and hardness, respectively. Compressive tests were performed using universal testing machine. A fully dense Al-1 wt.% SiC sample was obtained. Analysis of density and hardness values showed that the influence of applied pressure was more pronounced than heating rate while the influence of sintering temperature was more significant than sintering time. Within the range of parameters used, the highest values of the characterized properties were obtained at a sintering temperature of 600 °C, sintering time of 10 min, pressure of 50 MPa, and heating rate of 200 °C/min.

An attempt is made to cover the whole of the topic of biodegradable magnesium (Mg) alloys with a focus on the biocompatibility of the individual alloying elements, as well as shed light on the degradation characteristics, microstructure, and mechanical properties of most binary alloys. Some of the various work processes carried out by researchers to achieve the alloys and their surface modifications have been highlighted. Additionally, a brief look into the literature on magnesium composites as also been included towards the end, to provide a more complete picture of the topic. In most cases, the chronological order of events has not been particularly followed, and instead, this work is concentrated on compiling and presenting an update of the work carried out on the topic of biodegradable magnesium alloys from the recent literature available to us.

Although ceramics have many advantages when compared to metals in specific applications, they could be more widely applied if their low properties (fracture toughness, strength, and electrical and thermal conductivities) are improved. Reinforcing ceramics by two nano-phases that have different morphologies and/or properties, called the hybrid microstructure design, has been implemented to develop hybrid ceramic nanocomposites with tailored nanostructures, improved mechanical properties, and enhanced functionalities. The use of the novel spark plasma sintering (SPS) process allowed for the sintering of hybrid ceramic nanocomposite materials to maintain high relative density while also preserving the small grain size of the matrix. As a result, hybrid nanocomposite materials that have better mechanical and functional properties than those of either conventional composites or nanocomposites were produced. The development of hybrid ceramic nanocomposites is in its early stage and it is expected to continue attracting the interest of the scientific community. In the present paper, the progress made in the development of alumina hybrid nanocomposites, using spark plasma sintering, and their properties are reviewed. In addition, the current challenges and potential applications are highlighted. Finally, future prospects for developing alumina hybrid nanocomposites that have better performance are set.

Development of homogenous metal matrix nanocomposites with uniform distribution of nanoreinforcement, preserved matrix nanostructure features, and improved properties, was possible by means of innovative processing techniques. In this work, Al-SiC nanocomposites were synthesized by mechanical milling and consolidated through spark plasma sintering. Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray Spectroscopy (EDS) facility was used for the characterization of the extent of SiC particles’ distribution in the mechanically milled powders and spark plasma sintered samples. The change of the matrix crystallite size and lattice strain during milling and sintering was followed through X-ray diffraction (XRD). The density and hardness of the developed materials were evaluated as function of SiC content at fixed sintering conditions using a densimeter and a digital microhardness tester, respectively. It was found that milling for 24 h led to uniform distribution of SiC nanoreinforcement, reduced particle size and crystallite size of the aluminum matrix, and increased lattice strain. The presence and amount of SiC reinforcement enhanced the milling effect. The uniform distribution of SiC achieved by mechanical milling was maintained in sintered samples. Sintering led to the increase in the crystallite size of the aluminum matrix; however, it remained less than 100 nm in the composite containing 10 wt.% SiC. Density and hardness of sintered nanocomposites were reported and compared with those published in the literature.