Application Status and Prospects of Friction Stir Processing in Wrought Magnesium Alloys: A Review.

As an industrially reliable, controllable and effective deformation technique, friction stir process (FSP) can significantly refine the grain size, effectively activate prismatic plane and pyramidal plane slip systems of wrought magnesium alloys through intense plastic deformation and grain refinement, improving the mechanical properties and plasticity simultaneously. Therefore, more and more researchers are devoted to revealing the relationship between grain size, morphology and distribution of precipitated phases, and texture modification with the mechanical properties of magnesium alloys after FSP by means of some characterization techniques, such as electron backscattering diffraction, scanning electron microscopy and transmission electron microscopy. In this paper, the research results of FSP in wrought magnesium alloys in the last five years are reviewed. The fundamental principle and advantages of the FSP process are introduced, and the effects of the FSP process parameters and tool size on the microstructure characteristics, textile evolution, dynamic recrystallization mechanism and mechanical properties of Mg–Al–Zn, Mg–Li and Mg–Zn–Zr wrought magnesium alloys are analyzed emphatically. The preparation of ultrafine crystalline microstructures and achievement of superplastic behavior by modification of FSP are discussed in classification. In addition, the current status of metal additive manufacturing processes based on stirred friction processing (such as friction stir additive manufacturing and additive friction stir deposition) in wrought magnesium alloys is discussed in detail. Finally, the future research development and application of FSP in wrought magnesium alloys are prospected. Some reasonable suggestions are put forward to address the existing problems at this stage, which can provide references for further research in the future. [ABSTRACT FROM AUTHOR]