Investigating the microstructural and mechanical properties of novel ternary reinforced AA7075 hybrid metal matrix composite

This study investigates the comparison of the microstructural and mechanical properties of a novel ternary reinforced AA7075 hybrid metal matrix composite. Four samples, including AA7075 (base alloy), AA7075-5wt % SiC (MMC), AA7075-5wt %SiC-3wt % RHA (s-HMMC), and AA7075-5wt % SiC-3wt % RHA-1wt % CES (n-HMMC) were developed using the stir casting liquid metallurgy route, followed by the heat treatment. The experimental densities corresponded with the theoretical values, confirming the successful fabrication of the samples. A minimum density of 2714 kg/m3 was recorded for the n-HMMC. In addition, the highest porosity of 3.11 % was found for n-HMMC. Furthermore, an increase of 24.4% in ultimate tensile strength and 32.8 % in hardness of the n-HMMC was recorded compared to the base alloy. However, its ductility and impact strength was compromised with the lower values of 5.98 % and 1.5 J, respectively. This was confirmed by microstructural analysis, which reveals that n-HMMC has mixing issues and forms agglomerates in the matrix, which served as the potential sites of stress concentration leading to low impact strength and ductility. Nevertheless, the hybrid composites showed superior mechanical properties over the MMC and its base alloy

Extensive study of flow characters for two vertical rectangular polygons in a two-dimensional cross flow

Fluid dynamics problems have a significant impact on the growth of science and technologies all over the world. This study investigates viscous fluid’s behavior when interacting with two rectangular polygons positioned vertically and aligned in a staggered configuration. Two physical parameters, Reynolds Number and Gap spacings, are discussed using the Lattice Boltzmann Method for two-dimensional flow. Results are discussed in vortex snapshots, time trace histories of drag and lift coefficient, and power spectra analysis of lift coefficient. Nine distinct flow vortex streets are identified based on increasing gap spacings between the pair of two rectangular polygons. The vortex shedding mechanism is disturbed at small gap spacings and becomes optimal at large gap spacings. Different physical parameters of practical importance, like mean drag coefficient, root mean square values of drag coefficient, root mean square values of lift coefficient, and Strouhal number, approach the single rectangular polygon value at large gap spacings

Numerical investigation of flow features for two horizontal rectangular polygons

Studying fluid dynamics is crucial to advancing scientific knowledge and technological advancements worldwide. This study examines the behavior of a viscous fluid when it interacts with two horizontally positioned rectangular polygons arranged in a staggered arrangement. The lattice Boltzmann method is employed to analyze two-dimensional flow, specifically focusing on two physical parameters: Reynolds number, which is fixed at 150, and gap spacings, which vary simultaneously in X and Y directions. The results are analyzed by examining vortex snapshots, time trace histories of drag and lift coefficients, and power spectra analysis of lift coefficients. The progressive increase in the gap distances between the two horizontal rectangular polygons distinguishes seven separate flow vortex streets. The vortex shedding mechanism is disrupted at narrow gap spacings and reaches its ideal state at large gap spacings. There is the potential for the flow regime to be altered by the staggered alignment of rectangular polygons. Increasing the space between the polygons has a considerable impact on the flow characteristics brought about