Preparation of ZrB_2 based composites by reactive melt infiltration at relative low temperature

摘要

ZrB_2 based composites were prepared by a novel reactive melt infiltration process. The porous boron bars were used as preforms and infiltrated by the low melting Zr_2Cu intermetallic compound. Thermodynamics calculations revealed that B could react with liquid Zr_2Cu to form ZrB_2 as low as 1100 °C. Composites were prepared by heating the two materials to 1200 °C for 3 h in vacuum. The resultant composites were studied with XRD and SEM. ZrB_2 was identified to be the main constituent. The composites had a flexural strength of 414.3 MPa, a flexural modulus of 183.6 GPa, and a fracture toughness of 5.5 MPa m~(1/2).