Microstructure and fracture behavior of in-situ synthesized Mg2Si/Mg-2Al-Zn-2Gd composite

The Mg2Si reinforced Mg-2Al-Zn-2Gd composite was synthesized by in-situ solid state reaction and repeated plastic deformation (RPW) process. The XRD, SEM and TEM analysis results indicate that the RPW method can significantly decrease the second phase particle size as well as the matrix crystalline size, and the elastic modulus and yield strength of the composite increase with increasing the volume fraction of Mg2Si whereas the fracture strength and strain decrease. The interface between Mg2Si and matrix is smooth, and no crack initiation source has been found on the interface. The propagation of cracks formed in matrix during fracture can be obstructed by the second phase, and the increase of mechanical properties of the composite is attributed to the dispersed Mg2Si second phase particle and the refined matrix grain size.

Duke Scholars

Author Zhaohui Wang Pathology