水热还原法制备W-Cu复合粉体的工艺研究及表征

利用XRD、SEM、TEM等检测手段,对制备新型W-Cu合金过程中的产物显微组织进行研究和标定。结果表明:水热过程中,Na_2WO_4·2H_2O和Cu(NO_3)_2·3H_2O发生反应,水热反应产物主要由球形Cu WO_4·2H_2O和Cu_2WO_4(OH)_2的复合络合物组成,该络合物粉末分散性好,粒度均匀,平均粒径10~15 nm;煅烧后,水热产物转变为由CuWO_(4-x)、CuO和WO_3组成的混合氧化物粉体;经H2还原,氧化物粉末完全转化成W-Cu复合粉末,呈一种特别的W包覆Cu的近球形结构,平均粒径为20~60 nm,且Cu的存在对WO3的还原起催化作用。

Process research and characterization of W-Cu composite powders prepared by hydrothermal co-reduction technology

A special W coated Cu nano-composite powder was successfully synthesized via hydrothermal reaction and calcining-continuous reduction process,and the phase,morphology and microstructure of the powder obtained at different preparation stages were analyzed using XRD,SEM and TEM,respectively.Results show that the near-spherical CuWO4·2H2O and Cu2WO4(OH)2 complexes are produced by co-precipitation between Na2WO4·2H2O and Cu(NO3)2· 3H2O during hydrothermal reaction,and this complex powder has good dispersibility,a narrow size distribution of 10-15 nm without hard aggregate.After calcination,the precipitations are converted into a mixed oxide powders consisted of CuWO4-x,CuO and WO3 through dehydration and decomposition.After hydrogen reduction,the oxide powders turn into W-Cu composite powder completely,which presents a special nearspherical structure of W coated Cu,the particle size is 20-60 nm,at the same time,the presence of Cu plays a catalytic role on the reduction of tungsten oxide.