An exploration on microstructural observation and mechanical behavior of nanocrystallite Al 7017 alloy via mechanical alloying and uniaxial hot pressing

• Published in: Materials characterization 2021-01, Vol.171, p.110803, Article 110803
• Main Authors: Prashanth, M., Karunanithi, R., Mohideen, S. Rasool, Sivasankaran, S.
• Format: Article
• Language: English
• Subjects: Al 7017 alloy; FEA; HRSEM; HRTEM; Mechanical alloying; XRD
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2020.110803

The present research work investigates the detailed microstructural observation and mechanical behavior of nanocrystallite Al 7017 alloy prepared by Mechanical Alloying (MA) for a different milling times (0, 5, 10, 15, and 20 h)followed by uniaxial hot-pressing. The milled powders were characterized by X-ray diffraction analysis (XRD), High-Resolution Scanning Electron Microscope (HR-SEM), High-Resolution Transmission Electron Microscope (HR-TEM), and Particle Size Analyzer (PSA). The characterization of milled powder samples confirms the formation of nanocrystallite Al 7017 alloy through MA. X-ray peak broadening analysis was used to establish the various structural parameters such as crystal size, lattice strain, dislocation density, lattice parameter, and precise lattice parameter of milled powder and hot–pressed sample through Scherrer Equation and different models of Williamson–Hall methods [Uniform Deformation Model (UDM), Uniform Stress Deformation Model (USDM), and Uniform Energy Density Deformation Model (UDEDM)]. Additionally, a particle size analyzer was carried out to find the powder particle size and its distribution for different milling times. Powder morphology was characterized to determine the morphological change from flake type to an equiaxed spherical particle with a uniform dispersion of powder particle. Furthermore, it is used to analyze the development of nanograin MgZn2 precipitate during mechanical alloying. This work deliberates the influence of milling time on the mechanical properties (hardness, density, and compressive strength) of hot-pressed Al 7017 alloys. Finally, the Finite Element Analysis (FEA) was performed on hot-pressed samples to analyze the effective stress distribution and the results of the compression test are compared with the experimental analysis. •Very fine grain structures of FCC Al (ZnMg) has been achieved by MA method.•Crystal size and Dislocation density was estimated through X-ray peak broadening technique.•Lattice fringes for (111) plane with d-spacing 0.0291 nm.•Enrichment of mechanical properties was evaluated for Al 7017 alloy.