Mechanical and Microstructural Evaluation of Recycled AA۷۰۷۵ Swarf

In this research, after pressing in a cylindrical mold, the AA ۷۰۷۵ alloy swarf was melted and cast in a wet sand mold. After rolling and cutting, sheets with two different thicknesses of ۶ and ۲۰ mm were obtained. The sheets after homogenization were solutionized at ۴۸۵°C for ۳۰ and ۹۰ minutes, respectively, due to differences in thickness and thermal gradients. The solutionized samples were quenched in ۳ polymer solutions containing ۱۰, ۳۰, and ۵۰% Poly Alekylene Glycol. The results showed that melting, casting, rolling, and heat treatment of AA۷۰۷۵ alloy swarf similar properties to this alloy is achievable. Microstructural studies by optical microscopes (OM), Field Emission Scanning Electron Microscopy (FESEM), and X-ray diffraction (XRD) showed that by increasing the quenching rate after the solutionizing process, precipitation increases during aging. The tensile test results indicated that as the quench rate and internal energy increase, the diffusion driving force would increase the precipitation of alloying elements. Hence, this leads to an increase in hardness and reduction of its strain after aging.

کلیدواژه ها:

Aluminum ، ۷۰۷۵ ، Swarf ، Casting ، Heat Treatment