Preparation and Characterization of AlMgB_(14)-TiB_2 Composite by Field-activated and Pressure-assisted Synthesis

The pre-reacted AlMgB14 powders prepared by FAPAS were mixed with TiB2powers and then subjected to the temperature of 1500 ℃,the axial pressure of 60 MPa,the heating rate of 100 ℃ /min and dwelling time of 15 min.AlMgB14-30wt% TiB2 composites with ideal structures were successfully prepared.The microstructure and components of synthesized composites were observed and determined by scanning electron microscope(SEM),energy dispersive X-ray analysis(EDX),X-ray diffraction(XRD),and transmission electron microscope(TEM).The results show that the micro-hardness of the AlMgB14-30wt% TiB2 composites is 31.5 GPa and the fracture toughness K1C could reach 3.65 MPa.m1/2,which is consistent with those prepared by mechanical alloying/hot pressing.The microstructure analysis shows that the main toughening mechanisms of AlMgB14-TiB2composites are due to the hard phase dispersion strengthening,high-strength interface bonding.The FAPAS method might be used to synthesize AlMgB14-TiB2 composites at low costs with fast heating-up and efficiency.