ON THE ADOPTION OF λ_0 VALUE FOR ROSCOE''''S EQUATION

Considering the availability and derivation of Roscoe's equation for absolute viscosity calcula-tion,the method to adopt λ_0 value,so-called λ_f,was proposed by experimentally deter-mining relational curve of the measured height,H,of metal melt vs logarithmic oscillationdecrement,λ,extrapolating H into zero,if such corresponding λ value is taken.Experimentalresults show that the proposed method not only satisfies the availability of original equationbut also eliminate the effects of:“end and slippage”,so as to improve the accuracy for liquidCu and Sn examinations.     

对Roscoe粘度公式中λ0取值的研究

通过对Roscoe绝对粘度计算公式的适用条件和推导过程的研究,提出了由实验测量液态金属的深度H与振动对数衰减率λ的关系曲线,并将其外延到H→0时所对应的λ值,作为原λ_0的取值(记为λ_f)的方法,液态Cu和Sn的实验结果表明,所提出的方法不仅满足原公式的使用条件,而且消除了“端面和滑动”等影响,使计算准确。     

EFFECT OF Cu-Ni CONTENT ON THE CORROSION RESISTANCE OF （Cu-Ni）/（10NiO-90NiFe204） CERMET INERT ANODE FOR ALUMINUM ELECTROLYSIS

（Cu-Ni）/（10NiO-90NiFe204） cermet inert anodes containing metal Cu-Ni0, 5, 10, 15 and 20 wt pct were prepared and their corrosion resistance to Na3AlF6-Al2O3 melts was investigated. The results indicate that the content of metal Cu-Ni has little effect on the steady-state concentration of Ni in the electrolyte and the values could not be used to effectively differentiate their corrosion resistance. The steady-state concentration of Fe decreases from 304×10^-6 to 168×10^-6 and that of Cu increases from 21×10^-6 to 71×10^-6 with the content of metal Cu-Ni increasing from 0 to 20 wt pct. Post-examination shows that metallic phase Cu-Ni is corroded preferentially during electrolysis and many pores are left at the anode surface. Considering the corrosion resistance and electrical conductivity, the cermet containing metal Cu-Ni 5 wt pct should be selected and studied further.