In the present work, the effect of friction stir welding with different rotating and traverse speeds on
the microstructure and mechanical properties of Monel 400 and AISI 1020 carbon steel were
investigated. The employed rotating speed changed from 200 to 400 rpm, whereas the traverse speed
was 50 to 100 mm/min. Sound welds were obtained at the rotating speed of 200 rpm with the welding
speed of 50 mm/min, while a groove-like defect was formed when the traverse speed exceeded 200
mm/min. Mechanical properties of the joints were then evaluated using tensile tests, impact tests,
bending tests and micro-hardness at room temperature. Microstructure evolutions of welds were
characterized using optical microscopy. Welds showed high tensile, impact and hardness results.
