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以氧氯化锆(Zr OCl_2·8H_2O),硼酸(H_3BO_3),正硅酸乙酯(TEOS)和葡萄糖(C_6H_(12)O_6)为原料,以柠檬酸和乙二醇为螯合剂,采用溶胶凝胶、硼热/碳热还原工艺制备了Zr B_2-Si C超细复合粉体。研究了反应温度、原料配比等工艺条件对复合粉体合成过程的影响。研究表明:当n(B)/n(Zr)=2.5(摩尔比,下同),n(C)/n(Zr+Si)=8.0时,1500℃/2 h反应后可以合成高纯的Zr B_2-Si C超细复合粉体。利用SEM和TEM对复合粉体的显微形貌进行了表征,结果表明:实验条件下合成的Zr B2为六方柱状,其平均粒径约为500 nm,晶粒大小约为75 nm;Si C颗粒为短絮状物质,均匀分布在Zr B2周围。
Using ZrOCl_2 · 8H_2O, H_3BO_3, TEOS and C_6H_ (12) O_6 as raw materials and citric acid and ethylene glycol as chelating agents, Zr B 2 -Si C superfine composite powders were prepared by gel and boron thermal / carbothermal reduction. The effects of reaction temperature, ratio of raw materials and other technological conditions on the synthesis of composite powders were studied. The results show that when the reaction temperature is 1500 ℃ / 2 h, the reaction of n (B) / n (Zr) = 2.5 (molar ratio, the same below) and n (C) / n Zr B_2-Si C ultrafine composite powder. The morphology of the composite powder was characterized by SEM and TEM. The results show that the ZrB2 synthesized in the experiment has a hexagonal columnar shape with an average particle size of about 500 nm and a grain size of about 75 nm. Si C Particles are short flocs distributed evenly around ZrB2.