Oxidation Behavior of Cu-Pb Bearing Alloys

The oxidation kinetics of Cu-Pb bearing alloys was investigated under a temperature domain between 25 and 700 degrees C. It has been found that during oxidation process, lead was easy to diffuse in the channel formed inside the alloy and form oxide film on the surface of the alloy. The oxides formed by Pb at different oxidation temperatures show different morphologies, and there was no obvious change at 25 degrees C. However, the PbO formed by oxidation at 180 and 300 degrees C was spherical, and the Pb3O4 formed by oxidation at 500 degrees C was small flake distribution. At 700 degrees C, granular PbO was covered on the alloy surface. Sn and Cu were oxidized to SnO2 and CuO. Pb3O4 and PbO as oxidation products of Pb diffused at the alloy surface as the oxidation period increased. The oxidation weight gain curve of Cu-Pb alloy followed a parabolic law for 300 h at 25 degrees C. As the time increased, a straight line is noticed very close to zero. For a temperature range between 180 and 700 degrees C, the oxidation weight gain curves followed again a parabolic law.

Automated summary

The oxidation of Cu-Pb bearing alloys was studied in a temperature range of 25 to 700 degrees C. It was observed that lead could easily diffuse and form oxide films on the surface of the alloy during the oxidation process. The morphology of the oxides formed by lead at different temperatures varied. At lower temperatures, there was no significant change, while at higher temperatures, the morphology of the oxide films changed significantly, with granular lead oxide covering the alloy surface.