Friction Stir Consolidation of Aluminum AA5052 Alloy Machining Wastes

Abstract The purpose of this paper is to develop aluminum AA5052 alloy solid disc from machining wastes via friction stir consolidation (FSC) process & optimize its parameters: die rotational speed, pre-compact aspect ratio and processing time for better performance characteristics. At first, the required dedicated tooling are designed and built for the specific process. Then, the solid discs are fabricated from aluminum AA5052 alloy machining chips through FSC process in which the experimental parameters considered are rotational speed (315, 400 and 500 rpm), pre-compact aspect ratio (25.4/7, 25.4/5 and 25.4/3) and processing time (30, 45 and 60 sec). Based on the experiment, the compressive strength, hardness and microstructure of the consolidated solid disc are evaluated. Taguchi’s L9 orthogonal array is used to analyze and optimize the process. The results revealed that solid disc is successfully fabricated using FSC process using dedicated tooling, and rotational speed (500 rpm), compact aspect ratio (25.4/3) and processing time (60 sec) are optimal FSC processing conditions. The microsturcture of the solid disk shows finer and fully recrystallized grains in axial cross section orientation of the disc particularly in the central region. Moreover, the results show, the compressive strength and hardness of the solid disc are comparable to that of forged or cast disc and suitable for most engineering structural applications.