This paper explores new routes for flake powder metallurgy, with the aim of designing an effective route for fabricating metal matrix nanocomposites, combining high strength and good ductility. A new route that uses three speeds, instead of the two speeds characterizing the shift-speed ball milling (SSBM) route, has been suggested and implemented. The mechanisms of these routes were illustrated based on the intensity of ball-powder-ball collisions and the morphology evolution. The ball milled powder were characterized using filed emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Energy dispersive spectroscopy (EDS) to investigate the morphology evolution of the composites powder and the homogenous distribution of the SiC nanoparticles within the Al matrix. The reinforcing adequacy and interfacial bonding of 2 wt.% SiC nanoparticles in an inductively sintered composite has been investigated. Mechanical testing of the produced bulk composites resulted in achieving superior mechanical properties, characterized by 92% higher hardness, 180% higher yield strength, 101% higher ultimate strength, and 0% loss in uniform elongation, compared with those of regular SSBM. This is attributed to the homogeneous dispersion of the reinforcement into the Al matrix.

Reinforced steel bars (rebar) are extensively used in construction, and the main challenge is in minimizing corrosion due to oxide or passive layer breakdown. In contrast, dual-phase (DP) steel has good corrosion resistance. This study investigated the effect of Cl⁻ ions on the electrochemical corrosion behavior of DP rebar and conventional rebar. Corrosion behavior studies and electrochemical measurements were conducted on DP rebar and conventional rebar in simulated concrete pore solution with different concentrations of Cl⁻ ions. Microstructure analysis, surface morphology analysis, and corroded surface characterization were performed using optical microscopy, field emission scanning electron microscopy, and Raman spectroscopy, respectively. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements revealed that DP rebar has good passivity, leading to better corrosion resistance and greater strength compared to ordinary rebar. In addition, DP rebar showed better passivity behavior compared to conventional rebar in alkaline solution. Therefore, the presence of a dual phase (ferrite and martensite) in reinforced concrete structured steel induces good corrosion resistance.

In this study, Al-SiC nanocomposite was fabricated via powder metallurgy route using different innovative high-energy ball-milling techniques (HEBM). The powder mixture was consolidated using high-frequency induction heat sintering process (HFIHS). With the aim of studying the physical, mechanical, and tribological performance of the fabricated nanocomposites. Relative density, hardness, compressive yield strength, Young’s modulus, toughness, elongation, specific wear rate and coefficient of friction were experimentally investigated. A finite element model for the frictional process was built to find out the distribution of contact stresses as result of samples sliding. It was found that the highest the energy of the milling, the more improvement in the mechanical and tribological performance could significantly achieved due to the homogeneous distribution and the excellent bonding effect of the composite. In addition, field emission scanning electron microscope was used for studying the sliding surface morphology in order to explicate the mechanism of the dry wear process.

Advanced materials with high strength are in great demand for structural applications, such as in aerospace. It has been proved that fabrication strategy plays a vital role in producing composites to satisfy these needs. This study explores new strategies for flake powder metallurgy, with the aim of designing an effective strategy to achieve the highest possible mechanical strength for a metal matrix nanocomposite without changing the reinforcement fraction. Different strategies were used to regulate the mechanical properties for similar composites based on shift speed ball milling. Ultra-ductile composites on one hand, and ultra-strong composites on the other hand, were fabricated using similar composites. The results demonstrate that shifting the ball milling speed can be used to manipulate the mechanical properties of the composite to achieve the desired properties for any specific application.

In this work, the fabrication of three Al-2wt.% SiC nanocomposites processed by novel milling route was carried out. The beneficial influence of milling route on the corrosion passivation of the new fabricated composites was investigated. The cyclic polarization measurements have proved that increasing the time of ball milling highly reduced the corrosion of Al-SiC nanocomposite via reducing obtained corrosion current and so increasing the corrosion resistance. These results were affirmed by the electrochemical impedance spectroscopy experiments. The pitting corrosion of the manufactured composites was also reported, and its intensity decreased with the increase of ball milling time. The electrochemical experiments were also performed after expanding the exposure time in the chloride solution to 24 and 48. It was found that both the uniform and pitting corrosion decrease with prolonging the time. The study was complemented by examining the surface morphology and the elemental analyses for the different composites by using surface analyses techniques.