Wear characteristics of Al-Cr-O surface nano-composite layer fabricated on Al6061 plate by friction stir processing

摘要

Al-Cr-O hybrid nano-composites have been fabricated in-situ on the surface of Al6061 plate by friction stir processing (FSP) and their wear resistance has been investigated and compared with Al6061-T6 and friction stir processed (FSPed) Al6061-T6. A new procedure was introduced for applying the reinforcement particles, in which Cr_2O_3 powder was applied on Al6061 plate by atmosphere plasma spray and then the FSP was performed on the plate. During FSP due to thermomechanical condition, Cr_2O_3 was reduced with aluminum so pure Cr and Al_2O_3 were produced and as a result of reaction between Al and Cr, intermetallic compounds including Al_(13)Cr_2 and Al_(11)Cr_2 appeared. Dry sliding wear tests were applied using a reciprocating wear test. Results showed improved wear resistance in nano-composite samples. Al6061-T6 plate after FSP showed lower wear resistance than Al6061-T6 and nano-composites. This is due to the loss of hardening precipitates as a result of FSP.