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Abstract Compound casting was performed to investigate the bonding of the molten A356 aluminum alloy cast onto the SiC p /8009Al composite that was preheated at 395–450 °C. The bonding strength was measured by carrying out a tensile test. The interfacial microstructures were characterized by scanning electron microscopy, energy dispersive spectroscope, X-ray diffraction and electron backscattered diffraction. The results showed that the bonding strength increased by 37% when the preheating temperature increased from 395 °C to 420 °C, and decreased by 6.8% as the preheating temperature further increased to 450 °C. A transition zone where the Al 4.5 FeSi phases were distributed was formed. The grain size of the Al 4.5 FeSi phase increased while its density decreased from the SiC p /8009Al composite to A356 aluminum alloy. The transition zone widened from 1350 μm to 3200 μm as the preheating temperature increased from 395 °C to 450 °C. In addition, at the preheating temperature of 450 °C, the fracture position changed from the interface between the A356 aluminum alloy and transition zone (at the preheating temperature of 395 °C and 420 °C) to the interior of the transition zone. The interface formation mechanism and its effect on the fracture mechanism were also discussed. [ABSTRACT FROM AUTHOR]

In order to evaluate the role of external Si addition in the intermetallic formation of 8009 aluminum alloy, the mixed powders of AlSi20 alloy and rapidly solidified 8009 aluminum alloy were extruded and annealed under various annealing conditions. The employed characterization techniques included scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction and transmission electron microscope. The results showed that the formation of Al 4.5 FeSi phase was enhanced while the contents of Al 12 (Fe, V) 3 Si dispersion in 8009 aluminum alloy matrix and Si phase were decreased in the annealed AlSi20/8009 aluminum alloy with increasing annealing temperature (480 °C–540 °C) and annealing time (15 min–60 min at 540 °C). A novel nano-sized phase containing 5.58–6.98Al, 64.14–66.89Si, 25.59–26.20V and 1.91–2.65Fe (at. %) was observed at annealing temperature of 540 °C, which occupied a slice stacking morphology and had many sharp edges and corners. By comparing with the annealed 8009 aluminum alloys, the external Si addition was found to be responsible for the formation of Al 4.5 FeSi and the nano-sized phases in the annealed AlSi20/8009 aluminum alloys. The intermetallic formation mechanism and the role of external Si addition were also discussed based on experimental observations. • The mixed powders of AlSi20 and 8009Al were extruded and annealed. • The effects of annealing temperature and time were investigated. • A novel nano-sized phase was observed at annealing temperature of 540 °C. • The mechanism of intermetallic formation were discussed. [ABSTRACT FROM AUTHOR]

Despite extensive use of ER2319 welding wires for additive manufacturing of aluminum alloys in the aerospace and automotive field, the internal denseness, grain coarseness, and non-uniformity of additive-manufactured aluminum alloy parts are yet to be appropriately addressed. Thus, this study attempted to overcome this gap by using an ER2319 aluminum alloy welding wire to produce a uniform and fine-grained aluminum alloy using deformation-based friction rolling additive manufacturing (FRAM). The findings demonstrated that the FRAM-prepared materials were free of voids and cracks, with approximately equiaxed grains of only 4–6 μm. Further, the ultimate tensile strength (UTS) and yield strength (YS) of the deposited material in all directions differed only slightly, with the strengths in the longitudinal direction being 9.5 and 9.6% higher than that in the vertical direction, respectively. Furthermore, the combined UTS and elongation of the FRAM-prepared material are, to the best of the authors' knowledge, the best results reported for printed aluminum alloys using ER2319 welding wire. The interesting research results presented in this study are expected to have significant practical application implications and usher in further research in this field. [ABSTRACT FROM AUTHOR]