A geometric model for calcuating the visocsity of multi-component melt from related binary physicochemistry properties was derived based on Chou's thermodynamic geometric model.The model derved was employed to predict the viscosity of Au-Ag-Cu alloys.The results show that the calculated viscosity for Au-Ag-Cu alloys meet the experimental data very well.In addition,the viscosity of Bi-Sn-In systems was also predicted with this model.
Two types of disposable EMF hydrogen sensors for measurements of solute contents of liquid metals in situ in metal-refining processes and their general principles are introduced. The way to design new electrochemical sensors and the direction to develop new protonic conductors as new electrochemical sensors are discussed. The feasibility of protonic conductors worked as hydrogen pump in non-ferrous metal refining processes is discussed as well.
Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2·8H2O, HfOCl2·8H2O, Y(NO3)3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition: PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte.
The nanocrystalline Bi_2O_3^-Y_2O_3 solid electrolyte material was synthesized by pressureless reactive sintering process with Bi_2O_3 and Y_2O_3 nano mixed powder as raw materials, which was prepared by a chemical coprecipitation process. The study on the behavior of nano δ-Bi_2O_3 formation and its grain growth showed that the solid solution reaction of Y_2O_3 and β-Bi_2O_3 to form δ-Bi_2O_3 occurs mainly in the initial stage of sintering process, and nano δ-Bi_2O_3 crystal grains grow approximately following the rule of paracurve ((D—D_0)~2=K.t) during sintering process. After sintered at 600℃ for 2 h, the samples could reach above 96％ in relative density and have dense microstructure with few remaining pores, the δ-Bi_2O_3 grains are less than 100 nm in size.
Qiang ZhenLiangyan DongGang ShiRong LiWeiming HeJianqiang Liu
