Suoninen E, Herø H, Minni E
Scandinavian Institute of Dental Materials, Oslo, Norway.
J Biomed Mater Res. 1985 Oct;19(8):917-34. doi: 10.1002/jbm.820190804.
Electron spectroscopic studies of Au-Ag-Cu alloys of the type used for dental castings show that small additions (less than or equal to 3 wt%) of palladium reduce essentially the thickness of the sulfide layer formed on surfaces of samples treated in aqueous Na2S solutions. Relative to silver, palladium does not enrich in the sulfide, but statistically significant enrichment is found immediately below the sulfide layer. This enrichment probably takes place during the exposure of the substrate surface to atmosphere before the sulfiding treatment. The mechanism of the impeding effect of palladium on sulfiding is assumed to be a decrease in diffusion from the bulk alloy to the surface due to the enriched layer. The effect cannot be explained by changes in the electronic structure of the alloy due to palladium alloying.
对用于牙科铸件的那种类型的金 - 银 - 铜合金进行的电子能谱研究表明，添加少量（小于或等于3 wt%）的钯能显著减小在Na₂S水溶液中处理过的样品表面形成的硫化物层的厚度。相对于银，钯在硫化物中不会富集，但在硫化物层正下方发现有统计学上显著的富集现象。这种富集可能发生在硫化处理之前基底表面暴露于大气的过程中。钯对硫化的阻碍作用机制被认为是由于富集层导致从块状合金到表面的扩散减少。该效应无法用钯合金化导致合金电子结构的变化来解释。
