多孔SiC陶瓷/Zr基非晶合金复合材料动态压缩性能研究

The porous SiC ceramics/Zr-based amorphous alloy composites were prepared by the pressure-infiltration casting method. The influence of pressure-infiltration casting holding time and the properties of porous SiC ceramics on the dynamic compression performance were investigated with the split Hopkinson pressure bar (SHPB) and the S-4800 scanning electronic microscope (SEM). The results show that the dynamic compressive strength of porous SiC ceramic/Zr based amorphous alloy composites is significantly affected by the holding time and the properties of porous SiC ceramic. The composites exhibit the highest dynamic compressive strength which is1757 MPa with the porosity and average aperture size at 23.77% and 26.72 µm, respectively, at the pressure-infiltration casting temperature of 860℃ for 6.0 min. The fracture mode of the composite shows the brittle fracture under the dynamic compress load. The fracture morphology characteristics include the cleavage steps with different characteristics appearing in ceramic, different patterns of veins formed in Zr-base amorphous alloy, and the amorphous being kept in a relatively intact state. The Zr-based amorphous alloy can effectively hinder cracks expansion, resulting in the surrounding silicon carbide fracture and pushing movement of the amorphous phase; thus it would improve the dynamic compressive strength of porous SiC ceramic/Zr-based amorphous composites.