Preparation of ZrB_2 Ceramics by Self-propagating High-temperature Synthesis and Hot Pressing Sintering

摘要

ZrB2 ceramics were prepared by self-propagating high-temperature synthesis （SHS） and were sintered by hot pressing （HP）. The effects of the granularities and doses of raw materials in Zr-B2O3-Mg on SHS process and product were investigated. XRD and combustion temperature curves prove that the ideal SHS reactants of Zr-B2O3-Mg are 50 μm Zr powder, 75 μm B2O3 powder and 400 μm Mg powder with 45% excessive. The particle sizes of SHS product, acid-leached product, sintered product are 2-5 μm, 0.5-2 μm, 2-10 μm respectively. Chemical analysis indicates that the acid-leached product consists of ZrB2 （ 94.59%）, ZrO2 （3.87%） and H3BO3 （1.54%）. The sintered product has a relative density of 95.4%.