Mohsen Abbasi-Baharanchi - Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Fathallah Karimzadeh - Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran
Mohammad Hossein Enayati - Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran

The effects of friction stir processing (FSP) on the microstructure and mechanical properties of aluminum powder metallurgy (PM) parts was investigated. PM parts were then subjected to FSP at advancing speeds (v) of ۴۰-۲۰۰ mm/min and tool rotational speeds (ω) of ۸۰۰-۱۶۰۰ rpm. Microhardness (HV) and tensile tests at room temperature were used to evaluate the mechanical properties of the friction stir processed specimens. In order to evaluate microstructure of processed zone, cross-sections of FS processed specimens were observed optically. Based on the results obtained from investigation of the Zener-Holloman parameter (Z), average grain size decreased with decreasing working temperature and increasing working strain rate (equal to increasing Z). The finest grain size was ~ ۵.۴µm obtained at ω=۱۰۰۰ and v =۱۰۰ mm/min corresponding to a strain rate of ۲۷s-۱ at ۴۱۴ . This sample exhibited, the best mechanical properties with microhardness, yield stress, and tensile strength of the ۴۳ Hv, ۸۲ MPa, and ۱۱۸.۳ MPa, respectively.

Friction Stir Processing, Powder Metallurgy, mechanical properties, Rotational Speed, Traveling speed