Corrosion and leaching behaviors of Sn-based alloy in simulated soil solutions
(1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
2. School of Physics and Electrical Engineering, Zhoukou Normal University, Zhoukou 466000, China;
3. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
2. School of Physics and Electrical Engineering, Zhoukou Normal University, Zhoukou 466000, China;
3. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: The corrosion and leaching behaviors of Sn-0.75Cu solders and joints in NaCl-Na2SO4 and NaCl-Na2SO4-Na2CO3 simulated soil solutions were investigated compared with those in NaCl solution, aiming to assess the potential risk from the electronic-waste disposed in soil. The leaching kinetics of Sn reveals that the leaching amount of Sn increases with increasing the time. The amount of Sn leached from the joint is the largest in NaCl solution. and inhibit the leaching of Sn from the joints, but accelerate that from the solders. Meanwhile, the corrosion layer of the joint in NaCl solution is more porous, and those immersed in NaCl-Na2SO4 and NaCl-Na2SO4-Na2CO3 solutions are compact. The XRD results indicate that the main corrosion products on the solders and joints surfaces are comprised of tin oxide, tin chloride and tin chloride hydroxide. The potentiodynamic polarization measurements for the solders were discussed in the simulated soil solutions.
Key words: Sn-0.75Cu alloy; corrosion; leaching; simulated soil solutions