| Summary: | In this study, B _4 C _p /Al composites were prepared by microwave sintering using 20 vol% B _4 C and Al powder as raw materials. The effects of sintering temperature and time on the microstructure and properties of B _4 C _p /Al composites were studied. The results show that in the presence of microwave field, the pores amount at the B _4 C/Al interface and the densification has been changed. When the sintering temperature is 580 °C and the sintering time is 45 min, the B _4 C particles are dispersed. At this time, the B _4 C/Al interface is clean and tight together with few transient phase Al _3 BC _(s) that commonly generated in abnormally hyperthermal areas. When the temperature is enhanced or time prolonged, the liquid aluminum will appear in the composite, the fluidity of the aluminum matrix will increase greatly. A more serious aluminizing phenomenon will occur, resulting in the uneven distribution of B _4 C particles in the matrix. As for the properties, the optimized composite material exhibits the best compactness and Vickers hardness as 93.2% and 112.5HV _1 . The nanoindentation test reveals that the hardness and elastic modulus of interface are 8.494 GPa and 142.537 GPa.
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