In this study, accumulative roll bonding (ARB) process was used to produce Al/Al–12%Si multilayered composites at 300℃. Microstructure and mechanical properties of the composites were studied during various ARB cycles by field emission scanning electron microscope (FE-SEM), tensile test, and the Vickers microhardness test. The FE-SEM results revealed that, as the ARB cycle increases the thickness of individual Al and Al–12%Si sheets decreased. After the 5th cycle, Al–12%Si layers were necked, fractured and dispersed in the aluminum matrix. A new intermetallic phase Al3.21Si0.47 was formed at the Al/Al–12%Si interface, indicating that the ARB process could result in a metallurgical bonding. It was observed that the tensile strength of composites improved by increasing the ARB passes, i.e. the tensile strength of the Al/Al–12%Si composite was measured to be about 5.52 and 2.17 times that of the primary 1050-Al and Al–12%Si sheets, respectively. Observations reveal that the failure mode in ARB-processed composites is of the shear ductile rupture type. The microhardness of the Al and Al–12%Si alloys were raised to 110 HV and 121 HV after five cycles.

The multiscale hybridization of ceramic nanoparticles incorporated into polymer matrices reinforced with hybrid fibers offers a new opportunity to develop high-performance, multifunctional composites, especially for applications in aeronautical structures. In this study, two different kinds of hybrid fibers were selected, woven carbon and glass fiber, while two different ceramic nanoparticles, alumina (Al2O3) and graphene nanoplatelets (GNPs), were chosen to incorporate into a polymer matrix (epoxy resin). To obtain good dispersion of additive nanoparticles within the resin matrix, the ultrasonication technique was implemented. The microstructure, XRD patterns, hardness, and tensile properties of the fabricated composites were investigated here. Microstructural characterization demonstrated a good dispersion of ceramic nanoparticles of Al2O3 and GNPs in the fabricated composites. The addition of GNPs/Al2O3 nanoparticles as additive reinforcements to the fiber-reinforced polymers (FRPs) induced a significant increase in the hardness and tensile strength. Generally, the FRPs with 3 wt.% nano-Al2O3 enhanced composites exhibit higher tensile strength as compared with all other sets of composites. Particularly, the tensile strength was improved from 133 MPa in the unreinforced specimen to 230 MPa in the reinforced specimen with 3 wt.% Al2O3. This can be attributed to the better distribution of nanoparticles in the resin polymer, which, in turn, induces proper stress transfer from the matrix to the fiber phase. The hybrid mode mechanism depends on the interaction among the mechanical properties of fiber, the physical and chemical evolution of resin, the bonding properties of the fiber/resin interface, and the service environment. Therefore, the hybrid mode of woven carbon and glass fibers at a volume fraction of 64% with additive nanoparticles of GNPs/Al2O3 within the resin was appropriate to produce aeronautical structures with extraordinary properties.

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The present paper experimentally explores the influence of the fiber hybridization and layering sequence on crashworthiness behavior and deformation history of polymer/metal thin-walled pipes. Jute (J)/glass (G) reinforced epoxy over wrapped aluminum (Al) pipes were prepared via hand wet wrapping then subjected to axial quasi-static compressive loads. The load versus displacement plots and crashing indicators, i.e. peak crushing load ($${\mathrm{F}}_{\mathrm{ip}}$$ F ip ), mean crushing load ($${\mathrm{F}}_{\mathrm{m}}$$ F m ), total energy absorption ($$\mathrm{U})$$ U ) , specific energy absorption $$\left(\mathrm{SEA}\right)$$ SEA , and crush force efficiency $$\left(\mathrm{CFE}\right)$$ CFE were determined. Experimental results revealed that the maximum $$\left(\mathrm{SEA}\right)$$ SEA was recorded for Al/2J/4G/2J pipe with a value of about 42.92 kJ/g, with an enhancement of 20.56% in $$\left(\mathrm{SEA}\right)$$ SEA compared with pure Al-pipes. Al/2J/4G/2J specimens display the maximum ($$\mathrm{U})$$ U ) , $$\left(\mathrm{SEA}\right)$$ SEA , and $$\left(\mathrm{CFE}\right)$$ CFE and could be employed as energy absorbing members in automobiles.

As a class of promising cost-effective lightweight structures, metal-composite hybrids have rapidly emerged in automotive industry largely attributable to their outstanding multifunctional and crashworthy characteristics. The aim of this study is to investigate the potentiality of metal-composite cylinders for crash energy absorption applications. In this context, the crashworthiness performance, and the deformation history of jute (J)/glass (G) reinforced epoxy hybrid composite over wrapped aluminum (Al) cylinders were experimentally studied under quasi-static axial loading. Crashworthiness characteristics of the proposed cylinders were evaluated by measuring the average and peak crushing loads ($${\mathrm{F}}_{\mathrm{avg}}$$ F avg , $${\mathrm{F}}_{\mathrm{ip}}$$ F ip ), specific energy absorption ($$\mathrm{SEA}$$ SEA ), total absorbed energy ($$\mathrm{U})$$ U ) , and crush force efficiency ($$\mathrm{CFE}$$ CFE ). The influence of the number of J-layers on the deformation profiles has also been defined. Result revealed that the highest ($${\mathrm{F}}_{\mathrm{ip}}$$ F ip ), ($${\mathrm{F}}_{\mathrm{avg}})$$ F avg ) , and ($$\mathrm{SEA}$$ SEA ) noted for Al-3G-2 J-3G with values of 85.45 kN, 53.14 kN, and 39.99 J/g, respectively. The maximum ($$\mathrm{U}$$ U ) was documented for Al-8G with a value of 3535.89 J. The highest $$(\mathrm{CFE})$$ ( CFE ) was recorded for Al-2G-4 J-2G followed by Al-3G-2 J-3G with a value of 0.65 and 0.62, respectively. Al-3G-2 J-3G cylinders exhibit excellent energy-absorbing capacity and could be applied as energy-absorbing crashworthiness structures in automotive applications.

The effect of inducing circular holes into aluminum wrapped with glass/epoxy (Al/GFRP) pipes was investigated. Intact and holed specimens were evaluated in quasi-static axial compression after being constructed using the wet wrapping procedure. The effect of the induced holes' parameters i.e., hole diameter (d), number of holes (n), the hole position to specimen height ratio (L/H), on the crashworthiness of Al/GFRP structures was investigated. Results indicated that the existence of the cutouts visibly affects the values of crushing parameters. Increasing (d) remarkably reduces the total absorbed energy (U) and enhances the crushing force efficiency (CFE) of Al/GFRP pipes. Introducing two holes in two opposite faces with keeping their location constant reduces initial peak crush force $${(\mathrm{F}}_{\mathrm{ip}})$$ ( F ip ) , mean crush force $${(\mathrm{F}}_{\mathrm{m}})$$ ( F m ) , and U of Al/GFRP pipes but increases CFE. As the hole location goes to the lower edge of the pipe i.e., L/H increases, U obviously increases. The specimens with 4 mm holes in one side at medium height and specimens with 12 mm holes on one side at L/H = 0.8 had the best crushing parameters, respectively. The adequate design of the induced cutouts in thin-walled constructions is valuable to enhance the crashworthy performance of engineering structures.

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The Micro/meso-forming of commercially pure aluminum, AA1070, processed at room temperature by equal channel angular pressing (ECAP) with a die channel angle of 90° through 4 deformation passes has been conducted. Microstructure features, such as grain size, misorientation angle distributions and the developed texture during the four deformation passes of micro/meso-ECAP have been investigated by Electron backscattering diffraction (EBSD) technique. Then, hardness measurements over the cross-section of the processed samples were correlated with the EBSD analysis. EBSD scans revealed that extended shear bands (SBs) are formed and represent the microstructural feature induced during micro/meso-forming. Whereas, a non-uniform grain structure consisting of intensive low-angle grain boundaries was obtained in the first pass, a uniform ultrafine-grained structure of high-angle grain boundaries (in the range of 1-2 μm) was achieved at the fourth pass. Consequently, a significant improvement in the hardness value to 65.3%, with respect to the starting material, was achieved due to the enhancement of the fine grain structure. The texture analysis exhibited that the high plastic shear strain associated with micro/meso-scale ECAP was capable to develop a weak texture in the flow plane compared to the starting texture.