Experimental investigation on the effect of tool rotation speed on stir cast friction stir welded aluminium hybrid metal matrix composite

Abstract

Conventional fusion welding is limited to certain grades of alloys and materials. Solid-state joining method overcomes the disadvantages of fusion welding process. Friction stir welding (FSW) a solid state joining process, is extensively used to weld aluminium alloys for aerospace, marine automotive and numerous other applications of profitable significance. FSW uses a non-consumable rotating tool. Aluminium 6063 (AA6063) plays a vital role in the industrial metallurgy with magnesium and silicon as the alloying elements. AA6063 shows good mechanical properties and microstructural changes, when combined with reinforcements. In this study aluminium hybrid metal matrix composites (MMCs) is fabricated through stir casting process by varying the Zirconium oxide (ZrO2) (2%, 4% and 6%) and keeping the percentage of graphite (C) as constant (3%). The fabricated specimen is subjected to FSW technique by varying the tool rotation speed. Microstructure reveals that invariably all the specimens displayed recrystallized, uniformly distributed fine grained particles due to sufficient heat distribution. The maximum microhardness value of 79.18 HV was recorded for the joint made using the tool rotational speed of 1100 rpm for 6% ZrO2 and 3% C and a maximum tensile strength of 123.67 MPa for the same specimen.