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In this paper, an Ab-initio study was employed to study the properties of interfaces of Al3Y|Al. The interface strength, shear strength, structural stability, electronic density, bonding characteristics, stacking fault energy, and plasticity were all investigated. The interface with the stacking style of ABab or CBAcba has the greatest interface strength. The Al3Y(111)|Al(111) interface has the highest tensile stress of 13.39 GPa for rigid stretching; and 9.39 GPa for relaxation stretching. In the stretching process, the Al3Y(111)|Al(111) interface is prone to break on the Al3Y side. However, the Al3Y(010)|Al(010) and Al3Y(110)|Al(110) interface systems tend to fracture at the interface and Al side, respectively. Moreover, the differential charge density, electron localization function, and partial density of states (PDOS) demonstrate the newly formed chemical bonds at the interface, and the chemical bonds were formed by s-p or s-p-d hybrid orbitals. According to the Rice ratio and shear stress, these interfaces were found to be plastic and the Al3Y(111)|Al(111) interface has the best plasticity. This is significant because the formed interfaces are all advanced structure materials, which can be potentially used in automobile and aeronautical fields, even in some special industries. [ABSTRACT FROM AUTHOR]

Summary: Based on the consolidation theory raised by Fredlund, the solutions for the equal‐strain consolidation of unsaturated foundation with the prefabricated vertical drain considering smear effect and drain resistance are analytically formulated in this paper. Firstly, governing equations for excess pore pressures (i.e., excess pore‐air and pore‐water pressures) under the equal‐strain hypothesis are derived with the introduction of radial boundary conditions. Afterwards, the obtained coupled equations are solved by applying general integration, decoupling process, and Fourier sine series expansion. The smear coefficients and factors of drain resistance corresponding to air and water phases are both captured explicitly in the final solutions. Furthermore, the degenerated solutions are employed to verify the reliability of the current solutions. Finally, a parametric study is conducted to study the consolidation characteristics of the proposed foundation model against modeling sizes (S and N), smear coefficients (αa and αw), and drain resistance factors (Ga and Gw). [ABSTRACT FROM AUTHOR]

The uniaxial tensile tests of Hastelloy C-276 were performed under elevated temperature and strain rate. Considering the effects of different deformation parameters, the flow behaviour, microstructure and fracture characteristics were analysed based on the experimental data. From the rheological curves, the typical characteristics of dynamic recrystallisation were observed at a relatively high deformation temperature and low strain rate. Optical microstructures show that the degree of dynamic recrystallisation increases with an increase in temperature. The SEM micrographs show that the amount of precipitates increases with an increase in deformation temperature. Examination of the fracture morphology at high magnifications revealed that the coalescence of microscopic voids is responsible for the fracture failure. [ABSTRACT FROM AUTHOR]

The influence of Al–Ti–B grain refiners on the microstructures of Zr-containing Al–Zn–Mg–Cu alloy was investigated by optical microscopy and scanning electron microscopy, as well as through tensile and hardness tests. A poisoning effect occurred when the grain refiner was added to the Zr-containing alloy, and the grain size increased significantly. The precipitates in the alloy without the grain refiner were finely distributed, while the phases of the alloy with the Al–Ti–B refiner agglomerated at the grain boundaries, decreasing both the hardness and elongation. The addition of the grain refiner to the alloys markedly increased their hardness and elongation, when coupled with slow cooling, although the peak stress also decreased slightly. [ABSTRACT FROM AUTHOR]

In this paper, the formation energies and elastic constants of -Al2O3, MgO and AlN in both rock salt (cubic) and wurtzite (hexagonal) structures were investigated by first principles calculations. The results show that the formation energy being −17.8, −6.3, −3.06 and −3.46 eV/formula unit for -Al2O3, MgO, AlN (rock salt) and AlN (wurtzite). It suggests that in the ground state, -Al2O3 is relatively more stable than MgO and AlN. The elastic properties for a polycrystalline in the ground state were calculated with the obtained elastic constants, the elastic properties reveal the rock salt structure AlN is the hardest particles among all the inclusions, and all of these inclusions are classified as brittle materials, which is detrimental to the ductile nature of aluminum matrix. The calculated anisotropy index shows that the AlN (wurtzite) and -Al2O3 have a lower degree of anisotropy compared with MgO and AlN (rock salt). The calculated results are in good agreement with the values of experimental and other works. [ABSTRACT FROM AUTHOR]