Superior Mechanical Performance of Inductively Sintered Al/SiC Nanocomposites Processed by Novel Milling Route

Abstract

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.

Investigating the effect of mixing time on the crystallite size and lattice strain of the AA7075/TiC composites

“…The highest increment in the microhardness was 17.4 % at 6 h mixing time. The results are in resemblance with previous studies [27,28]. It is not- ed from above results that reduction in crystallite size of the composites can be considered as one of the governing factors in enhancement of the microhardness of the AA7075-TiC composites.…”

Influence of Milling Route on the Corrosion Passivation of Al-2%SiC Nanocomposites in Chloride Solutions

“…Three aluminum metal matrixes reinforced with 2 wt.% SiC nanoparticles were synthesized via different powder metallurgy routes. The fabrication of these three nanocomposites has been reported in the previous study [20]. In brief, the three routes have similar first and second ball milling stages and differ in the third stage as summarized in Table 1.…”

“…The XRD patterns were obtained at 2 • /min scan rate, 10 to 90 • angle range, and 0.02 • a locked scan type as an increment. More details about XRD results can be found in the earlier investigation [20]. The SEM and the EDX analyses were also investigated.…”

“…The inner layer is dominating impedance at high frequency area, while the outer layer (porous layer) is dominating at low frequency range [32,33]. Further, Q (with its "n" value is circa 1) is considered as double layer capacitors, which gives a confirmation that the outer layer has some porosities and is dominating the impedance at the low-frequency region [20,26]. In addition, the presence of a C dl reveals that prolonging ball milling time enhances the passivation of the surface against corrosion in the chloride solutions.…”

Alloying Elements Effects on Electrical Conductivity and Mechanical Properties of Newly Fabricated Al Based Alloys Produced by Conventional Casting Process

“…The effect of using silver into Aluminum alloys have been reported, but still quite little research articles are available in this field. The mechanical properties and microstructures of Al–Mg–Cu–Ag alloys are very sensitive to heat treatment parameters and deformation conditions [ 15 , 16 , 17 ]. The addition of silver to aluminum-4 wt%-copper alloy slows down the ageing rate of the low temperature limit, which provides a chance for hardening to take place by the expanding ageing time.…”