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Composite materials are an important class of economical structural materials with unique properties that expand the scope of mechanical engineering in various industries. One of the most interesting metal composite materials is metal structures with low cost of reinforcement and availability for mass production. Due to the development of the structural requirements of some aircraft components, the development of the accelerated aging process becomes necessary to observe and understand the aging of aluminum alloys and predict the effect of this process on the mechanical behaviors of these alloys under temperature. In this research boron carbide (B4C) is reinforced in the aluminum matrix composites to increase the more conductivity and characterized for their mechanical properties such as hardness and tensile strength. Al-5%Cu aluminum alloy metal matrix composites will be reinforced with Boron Carbide (B4C) particles up to 2, 5 and 7 % was produced by stir casting. Particulates may subsequently add using the squeeze casting process. The squeeze casting technique decreased the porosity of the final composites. The modes of aging of MMC reinforced with B4C particles are determined. It is shown that when aging at 225 °C with an increase in the content of B4C particles to 7%, the maximum hardness is reached after 7 hours, while in the matrix alloy after 9 hours. Aging at 250 °C reduces the time to reach maximum hardness by 1 hour.

The TiB2/Al particle reinforced composites were prepared successfully through metal-salt reaction with different process conditions (mechanical stirring, one-stage and two-stages of ultrasonic vibration). It was usually taken more than 60 min to complete metal-salt reaction under mechanical stirring condition, lots of reinforcement agglomerations and residual intermediate such as Al3Ti was in the matrix. The reaction time was greatly shortened from 60 min to 5 min and particle agglomerations were eliminated successfully by the introduction of ultrasonic vibration at 850 °C. Through the introduction of ultrasonic vibration at 730 °C, not only most of the residual Al3Ti phase was broken or dissolved, but also the size of TiB2 was refined. The composite prepared by two-stage ultrasonic vibration has the optimal improvements of yield strength and ultimate tensile strength, which increased by are 108% and 98% respectively, hardness increased 61.5%. When only introducing the first stage of UVT, the elongation decreased from 34% to 20% owning to lots of rod-like Al3Ti in the matrix, after the second stage of UVT, the elongation restored to 33%. The effects of ultrasonic vibration on phase transformation, microstructure, and mechanical properties were studied by x-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and Electron Backscattered Diffraction (EBSD). Moreover, the effects of Orowan strengthening, thermal expansion mismatch strengthening, and grain refinement strengthening on mechanical properties were also discussed.

Aluminum matrix composites are chosen for electronic, aircraft, and automobile components due to the lightness of their weight and high specific strength. High-quality aluminum-based composites are well known for their microhardness and high refractoriness performance in aerospace with the advantage of structural applications. The boron carbide ceramic as a reinforcement plays an outstanding function in the base matrix to enhance the mechanical behavior of the composites. The present effort revealed that the synthesized composites were fabricated by the stir casting process and B4C having a particulate size of 50 µm were reinforced from 1% to 15% in the AA 6061 by varying weight percentages. Microhardness such as Brinell and Rockwell hardness moreover impact testing was performed experimentally. The mechanical characterization of fabricated composites with high mechanical performance-based composites has been investigated in this research work. Using microstructural characterization by scanning electron microscopy and x-ray diffraction we examinded high mechanical performance-based composites.

The equibiaxial bend behavior of laminate carbon fiber fabric reinforced aluminum matrix composites is modelled and assessed. Analytical modelling and finite element analysis are comparatively investigated to study the mechanical properties, with particular focus on the elastic modulus and flexural strength. The investigation allows evaluating how far the experimental results deviate from idealized assumptions of the models, which provides insight into the composite quality and the effectiveness of the used laminate squeeze casting technique. Specifically, discrepancies shed light on the interlaminate and fiber-matrix interface bond as well as on the stability of the laminate layers during fabrication. The two model approaches are in good agreement with differences below 8%. Moreover, the models agree with experimental data in predicting an overall improvement in properties with increasing carbon fiber content up to 4.89 vol%. Overall, the composite samples outperform the model predictions, which indicates good interface bonding. However, microstructure investigations also indicate that the outperformance is partly caused by a shifting of the carbon fibers during squeeze casting closer to the later bend tensile loaded surface due to their lower density compared to aluminum. The result is higher load bearing capacity of the composites than estimated by the models that assume perfectly symmetrical composite structure. The experimental outperformance in ultimate flexural strength vanishes at higher carbon fiber contents. This is due to imperfect interlaminate and fiber-matrix interfaces where some defects such as pores, carbides and oxide particles tend to locate, leading to damage initiation and potentially interface failure.

The authors investigated the effect of mechanical activation and self-propagating high-temperature synthesis (SHS) on the phase composition of composite materials of Al-TiO2-B system. It has been shown that with increasing the duration of mechanical activation of initial powders the amount of crystalline boron-containing phases in the mixture increases. X-ray diffraction analysis of powder mixtures after SHS allows making conclusion about necessity of activation for at least 45 min to obtain a target compounds. Experimental results allow reasonably choosing the modes of mechanical activation for production of aluminium matrix composites with specified composition and controllable properties.

The preparation of graphene-reinforced metal matrix composites is promising. Graphene has many excellent properties as a reinforcement. However, easy reunion and poor wettability are the challenges for the preparation of graphene-reinforced metal matrix composites. Aiming at the problems of graphene being uniformly dispersed in the matrix and the interface bonding strength between the graphene and the matrix, this article will discuss the influence of powder mixing method and molding process on composite materials during the preparation of graphene-reinforced aluminum matrix composites.

Graphene nanoflakes-reinforced aluminum matrix composites (GNFs/Al) with 1.0 wt.% GNFs were fabricated by a spark plasma sintering (SPS) method under two different condition. The microstructural and interfacial characteristics of the two composites were systematically investigated, and their different tensile mechanical properties were found to depend strongly on the GNFs/Al interfacial characteristics. Prolonged sintering in SPS should be avoided as it promotes obvious interfacial reaction that degrades the mechanical properties. The enhanced mechanical properties of the GNFs/Al composites in this study can be ascribed to their exquisite microstructures, specifically the well-maintained structure of raw reinforcement, the uniform GNF distribution and their parallel alignment with the tensile direction, the absence of mass interfacial reaction, and the good interface bonding.

The mechanical properties and wear behavior of aluminum matrix reinforced with steel machining chips was investigated. Pure aluminum was reinforced with 5, 7.5, and 10 wt% steel chips with an average size of 100 μm using powder metallurgy technique. Aluminum reinforced with 5 and 10 Wt.% SiC particles were manufactured for comparison. The investigation showed clear evidence that the addition of steel machining chips resulted in significantly low porosity levels in the aluminum matrix composites compared with the use of SiC as reinforcement. The mechanical properties (tensile and hardness) as well as the wear resistance were also observed to improve with the use of the steel machining chips as reinforcement. The results demonstrate the capability of steel machining chips to act as efficient reinforcing material and a reliable cost effective candidate in the development of aluminum matrix composites.

Compared to conventional cutting, the processing of materials by electrochemical machining offers some technical advantages like high surface quality, no thermal or mechanical impact on the work piece and preservation of the microstructure of the work piece material. From the economic point of view, the possibility of process parallelization and the absence of any process-related tool wear are mentionable advantages of electrochemical machining. In this study, based on experimental results, it will be evaluated to what extent the electrochemical machining is technically and economically suitable for the finish-machining of particle- reinforced aluminum matrix composites (AMCs). Initial studies showed that electrochemical machining - in contrast to other machining processes - has the potential to fulfil demanding requirements regarding precision and surface quality of products or components especially when applied to AMCs. In addition, the investigations show that processing of AMCs by electrochemical machining requires less energy than the electrochemical machining of stainless steel. Therefore, an evaluation of electrochemically machined AMCs - compared to stainless steel - from a technical and an economic perspective will be presented in this paper. The results show the potential of electro-chemically machined AMCs and contribute to the enhancement of instruments for technical-economic evaluations as well as a comprehensive innovation control.