Evaluation of thermal history and defect in friction stir processing of as-cast magnesium AZ91

Abstract

Friction stir processing (FSP) is a thermos-mechanical process for modifying the microstructural and material properties of metals. FSP also can be used for mechanical alloying and producing metal matrix composites. Due to creation of longitudinal cracks and tunneling cavities throughout the processing path, FSP of AZ91 is difficult and also sensitive to processing temperature. In this study, the effect of processing parameters such as the traverse and rotational speeds and the dimension of the tool pin on the temperature history experienced by material were investigated. Additionally, a minimum temperature required to produce a defect-free specimen was presented. 2018 Trans Tech Publications, Switzerland.