论文部分内容阅读
The effect of Sn on the color and tishing of Cu-Mn-Zn alloys is investigated quantitatively. Using the CIE LAB color system,color parameters such as L*, a* and b* are selected to describe the surface color of alloys while the color difference (△E*)is used to evaluate the color stability. The results show that with the increase of Sn, the color change of Cu-Mn-Zn alloys is greatly reduced and the corrosion resistance in the synthetic sweat is improved dramatically. However, up to 4.4 wt pct Sn does not change the color of Cu-Mn-Zn alloys much. XPS and AES are employed to analyze the tished surface. It is proved that a Sn enriched film is formed and Sn takes the form of Sn oxide. This thin and protective oxide film can prevent alloy from further tishing.