In-situ Synthesized ZrB_2p/A356 Composites by Magnetic-Chemical Reaction and Its Characterization

ZrB2 particle reinforced A356 matrix composites were prepared using A356-K2ZrF6-KBF4 as reaction system by magnetic-chemical in-situ reactive synthesis method.Phase composition,microstructure and mechanical properties of the composite were investigated by means of XRD,SEM and tensile test machine.The results show that the obtained ZrB2 particles with average size of 0.1-0.3 μm had regular hexagonal morphology and distributed uniformly in the matrix alloy.Compared with the traditional in-situ reaction,the pulse magnetic field could effectively improve the chemical reaction process,prevent the particles agglomeration and growth,make the particles distributed more uniformly.The tensile strength of the composites reached 273.1 MPa,which was increased by 22.19% compared with that of the composites without pulse magnetic filed (223.5 MPa).And the elongation reduced.The obvious dimple-crack characteristics on the tensile fracture surface at room temperature of the composites were observed,and the fracture mechanism was plastic fracture.