Synthesis and densification of zirconium diboride prepared by carbothermal reduction

• 作 者: Tao Gui Xing-Ming Wang Lei Yang Yu-Yang Liu Xue Bai Li-Jun Wang Bo Song
• 机 构: Division of Metallurgy and Materials for Rare Metals, General Research Institute for Nonferrous Meta
• 出 处: 稀有金属（英文版）
• 发表日期: 2018年12期
• 关键词: Zirconium diboride Carbothermal reduction Grain growth Morphology control Deep d

Using boron powder as additive,the preparation of zirconium diboride (ZrB2) by carbothermal reduction was investigated.The results show that the carbothermal reduction cannot be completely done until the temperature is more than 1900 ℃.The ZrB2 particles prepared without boron (B) additive at 1900 ℃ for 3 h are rodlike and show a preferential grain growth along [001] direction.B addi-tive changes the heat effect of the raw materials.With B additive,the morphology of ZrB2 particles ts to be regular shape.The average particle size is about 3.6 μm with 2.5 wt％ B additives.With more B additive,the shape of particles ts to be round like and the average particle size is decreased to 2.3 μtm when 5 wt％ B is added.The existence of oxides in grain boundary is a key factor to keep ZrB2 ceramic from deep densification.Using ZrB2 powder prepared with 5 wt％ B additives,by controlling carbon content in ZrB2 powder,ZrB2 ceramic with 93％ relative density is hot-pressed.