Al-Mg-Si系合金の粒界腐食に及ぼすCu含有量の影響 The effect of Cu content on susceptibility to intergranular corrosion of Al-Mg-Si alloy
Electrochemical measurements showed the results as follows. Pitting potential of solution heat treated alloy increased with Cu content. After precipitation heat treatment at 200°C for 60 min and for 180 min, pitting potential of Cu containing alloys decreased to −720~−730 mV (vs. SCE), accompanying intergranular corrosion. Dissolution potential of Mg<sub>2</sub>Si compound was found to be −730 mV (vs. SCE), which agreed with the pitting potential of precipitation heat treated Al–Mg–Si–Cu alloys. Intergranular corrosion of Al–Mg–Si–Cu alloys was concluded to be caused by preferential dissolution of less noble Mg<sub>2</sub>Si phase at grain boundary.
軽金属 47(5), 285-291, 1997-05-30
The Japan Institute of Light Metals