以仲钨酸铵和硝酸锆为原料,采用分步水热法结合煅烧和二次氢还原工艺制得ZrO2掺杂钨合金粉末。利用XRD、EDS、SEM、TEM等检测手段对不同制备过程产物的相结构、形貌及相转变进行分析。结果表明:仲钨酸铵与硝酸进行水热反应,生成一种钨酸,其分子式为1.5WO3·2H2O;硝酸锆与氨水进行水热反应后生成单斜结构ZrO2;通过液-液掺杂方式使这两种产物混合均匀,干燥后得前驱粉末。经500-550℃煅烧后,立方结构1.5WO3·2H2O转变为单斜结构WO3。经800℃×2h+900℃×2h二次氢还原后得到ZrO2掺杂钨合金粉末,其平均粒径为10-20nm。通过对比实验可得,掺杂ZrO2可起到细化钨晶粒的作用。
ZrO2-doped tungsten alloy powders were prepared with step hydrothermal method combined with calcination and two-stage hydrogen reduction process using APT and zirconium nitrate as raw materials.Phase composition,morphology and phase transformation were analyzed of the products from different preparation process by XRD,EDS,SEM and TEM.The results show that a tungstenic acid of 1.5WO3·2H2O is generated in the hydrothermal reaction of APT and nitric acid,and monoclinic ZrO2 is generated in the hydrothermal reaction of zirconium nitrate and ammonia.The above products were uniformly mixed by liquid-liquid doping and dried to obtain the precursor powders.After calcination of the precursor powders at500-550 ℃,cubic 1.5WO3·2H2O transforms into monoclinic WO3.After 800 ℃×2h+900 ℃×2hhydrogen reduction,ZrO2-doped tungsten alloy powders were obtained with average particle size of 10-20nm.Based on the results of contrast experiments,it is concluded that doping ZrO2 can play a role in refinement of tungsten grains.