水热法制备ZrO_(2)掺杂钨粉体过程中的粉体形貌与相转变  

Morphology and Phase Transition of ZrO_(2) Doped Tungsten Powder Prepared by Hydrothermal Method

作　　者：叶家豪 赵云超[1] 李洲[2] 朱晨辉 徐流杰[2] Ye Jiahao;Zhao Yunchao;Li Zhou;Zhu Chenhui;Xu Liujie(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471003,China;National and Local Joint Engineering Research Center of Metal Material Wear Control and Forming Technology,Henan University of Science and Technology,Luoyang 471003,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学,金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003

出　　处：《稀有金属》2023年第6期825-833,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(U2004180);国家重点研发计划重点专项项目(2017YFB0306000)资助。

摘　　要：为了探究掺杂不同含量、不同晶型ZrO_(2)是否对W合金粉体微观形貌产生影响及相转变,通过水热合成、煅烧、两段氢还原工艺制备了不同含量及不同晶型的ZrO_(2)掺杂W合金粉体,研究了ZrO_(2)对W合金粉体微观形貌、尺寸的影响。结果表明:水热合成的ZrO_(2)掺杂含量W合金粉体前驱粉由仲钨酸铵(APT)和ZrO_(2)两相构成,粉体团聚现象比较严重,粉体颗粒主要呈片状或块状,粒径较分散。煅烧后粉体由WO_(3)和ZrO_(2)两相构成,颗粒细小而分散。经二段氢还原后,粉体转变成W和ZrO_(2)两相,粉体颗粒大部分呈近球形,分散均匀。与稀土氧化物细化粉体颗粒作用机制较类似,ZrO_(2)的存在从促进形核、抑制生长两方面影响W颗粒长大的化学气相沉积反应而细化粉体颗粒,且掺杂量越大粉体越细小。纯W粒径约为15.329μm,掺杂ZrO_(2)可使粉体粒径减小到3.552μm左右。同样掺杂量的条件下,ZrO_(2)晶型对粉体的微观形貌和尺寸无明显影响。Many researchers have studied how to improve the properties of tungsten alloy to meet the needs of industrial development,and they found that the mechanical properties of tungsten alloy can be greatly improved by doping rare earth oxides.However,due to the limited rare earth resources and strategic vision,it is very important to find materials that can replace rare earth oxides.Therefore,zirconium oxide(ZrO_(2))was used instead of rare earth oxide,and different contents of zirconium oxide were doped in tungsten(W)powders,which was expected to refine W alloy powders and lay a foundation for the subsequent preparation of tungsten alloy with excellent performance.It was known that zirconia had reversible phase transition at different temperatures,and it was a common monoclinic phase(m-ZrO_(2))at room temperature.The monoclinic phase changed into tetragonal phase(t-ZrO_(2))at above 1170℃ and cubic phase(c-ZrO_(2))when the temperature exceeded to 2370℃.In order to find out whether different crystal forms of ZrO_(2) affected the morphology of powders,different proportions of Y_(2)O_(3) were doped as stabilizers,so that t-ZrO_(2) and c-ZrO_(2) could be obtained at room temperature.Ammonium paratungstate(APT),zirconium nitrate,yttrium nitrate and urea were used as raw materials for medium W alloy powders.Firstly,the weighed APT was calcined at 120℃for 18 h in a drying oven,then poured into a roller,and then added with appropriate amount of distilled water,and stirred for 24 h.At the same time,zirconium nitrate,yttrium nitrate and urea were dissolved in proportion,then poured into a high-pressure reaction kettle,and kept at 180℃ for 18 h in the drying oven.Then,the above two liquids were fully stirred and mixed by liquid-liquid doping,dried,crushed by a pulverizer and sieved by a 350μm sieve.Then that prepare powders were calcine at 550℃ for 2 h.Finally,after two-stage hydrogen reduction(reduction conditions:600℃×4 h+950℃×6 h),ZrO_(2) doped W alloy powders were obtained.In addition,the influence of ZrO_(2

关 键 词：水热法 W合金粉末 ZrO_(2)晶型 形貌 相转变 

分 类 号：TF841.1[冶金工程—有色金属冶金]