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

摘要

ZrB_2 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-B_2O_3 -Mg on SHS process and product were investigated. XRD and combustion temperature curves prove that the ideal SHS reactants of Zr-B_2O_3-Mg are 50 mu m Zr powder, 75 mu m B_2 O_3 powder and 400 mu m Mg powder with 45 percent excessive, The particle sizes of SHS product, acid-leached product, sintered product are 2-5 mu m, 0.5-2 mu m, 2-10 mu m respectively. Chemical analysis indicates that the acid-leached product consists of ZrB_2 (94.59 percent), ZrO percent (3.87 percent) and H_3BO_3(1.54 percent ). The sintered product has a relative density of 95.4 percent.