La传感器在测定铝液凝固过程中La活度研究

微量稀土加入铝或铝合金中，如果加入方法、数量、时间得当，可明显改善材料的多项性能．稀土对铝及铝合金的影响规律和作用机理，已取得了一些进展，但对稀土铝合金的热力学性质，尤其是溶解态稀土的研究少有报导［‘，2］．本工作采用L即．95C。。。。FZ。。多晶作为固体电解

Study on the Effect of La-activity in La-sensor on the Determination of the Liquefaction of Aluminum

La0.95Ca0.05F2.95 polycrystalline solid electrolyte tube was prepared. The La sensor was made by using such solid electrolyte tube, pure La as reference electrode and Mo wire as lead wire. the cell can be experssed as:
Mo|La(S)| La0.95Ca0.05F2.95|[La]Al|Mo Ceramal
The activities of dissolved La in liquid (750℃) aluminum with three different La concentrations were determined. The change of La activity and po2 with temperature in the solidfication process (750-500℃) was also determined, the result showed some regularities existed. In the course of rising and falling of temperature the La probe can be used repeatly 2-3 times.