Grenga H E, Carden J L, Okabe T, Hochman R F
J Biomed Mater Res. 1975 Mar;9(2):207-11. doi: 10.1002/jbm.820090209.
The surface properties of Ag3Sn are important in the amalgamation process so that mechanical abrasion is generally necessary to get a satisfactory amalgam. Therefore, the present study was undertaken to characterize the surface of Ag3Sn after several types of surfaces treatments. Homogeneous polycrystalline rods of Ag3Sn were prepared in vacuo from high purity (99.99%) Ag and Sn. Specimens were sliced from these rods and prepared as follows: (1) mechanically polished, (2) polished as in (1) and allowed to sit in air for three days and (3) polished as in (1) and electrolytically etched. Each of these specimens was examined by Auger electron spectroscopy. The results showed that after mechanical abrasion the surface film was primarily oxide and the Ag to Sn ratio was lower than the bulk composition, indicating preferential oxidation of Sn. After sitting in air sulfur was also present on the surface and the Ag to Sn ratio was greater than that immediately after polishing, indicating the formation of Ag2S. After electrolytic etching some oxide was still present, but only a trace of sulfide was found. However, the Ag to Sn ratio was greater than that for mechanically polished specimens, indicating preferential dissolution of Sn. Therefore, it is seen that the surface preparation of Ag3Sn has a marked effect on Ag and Sn concentrations and the nature of films at the surface.
Ag3Sn的表面性质在汞齐化过程中很重要，因此通常需要进行机械研磨才能获得令人满意的汞齐。因此，本研究旨在对经过几种表面处理后的Ag3Sn表面进行表征。由高纯度（99.99%）的Ag和Sn在真空中制备出均匀的Ag3Sn多晶棒。从这些棒上切下试样并按以下方式制备：（1）机械抛光，（2）按（1）进行抛光并在空气中放置三天，（3）按（1）进行抛光并进行电解蚀刻。对每个试样进行俄歇电子能谱分析。结果表明，机械研磨后表面膜主要是氧化物，Ag与Sn的比例低于整体成分，表明Sn优先氧化。在空气中放置后，表面也存在硫，且Ag与Sn的比例大于刚抛光后的比例，表明形成了Ag2S。电解蚀刻后仍存在一些氧化物，但仅发现微量硫化物。然而，Ag与Sn的比例大于机械抛光试样的比例，表明Sn优先溶解。因此，可以看出Ag3Sn的表面处理对表面的Ag和Sn浓度以及膜的性质有显著影响。
