Masoud Yavari Nouri - Department of Mechanical Engineering, University of Birjand, Iran
S. M. Hossein Seyedkashi - Mechanical engineering department, University of Birjand
Moosa Sajed - Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran

In this paper, a new production method of aluminium/steel double-layered wire is proposed using a modified friction stir extrusion process. The core and coating were made of St۳۷ steel and aluminium alloy, respectively. For extruded specimens, the effects of the main process parameters including tool rotational speed and feed rate were investigated on adhesion strength and surface cracks. The tool rotational speed was studied at two levels of ۳۰۰ and ۶۰۰ rpm, and the feed rate at two levels of ۴ and ۱۲ mm/min. Pull-out test was carried out using a tensile test machine to evaluate the adhesion strength. Surface cracks were evaluated by the liquid penetrant test. The results suggest that the modified friction stir extrusion process can be used successfully to produce dissimilar double-layered wires. With the right combination of tool rotational speed and feed rate levels, a dissimilar double-layered wire can be produced with a high adhesion strength and good surface quality. No cracks were observed in specimens produced with the feed rate of ۱۲ mm/min and rotational speed of ۶۰۰ rpm. The maximum adhesion strength was ۲۸۶۷.۱۳ N that was achieved with a tool rotational speed of ۳۰۰ rpm and feed rate of ۱۲ mm/min.

Adhesion strength, Crack, Double-layered wire, Friction Stir Extrusion, Liquid penetrant testing