The protective characteristics of films formed on the AM60 magnesium alloy by treatments with trimethoxysilanes have been studied. The following silanes were examined: n-propyltrimethoxysilane (PropS), n-octyiltrimethoxysilane (OctS), 1,2-bis-trioxymethylsilylethane (BTES), bis-3(trimethoxysilyl)propylamine (Bis-TMPA), metaacryloxypropyltrimethoxysilane (PropS-MA) . The Mg alloy was treated in aqueous solutions of various silanes at 80°C. The influence of silane concentration, pH of the solution, time of immersion, time of hydrolysis, curing time at 100°C at the end of treatment was examined. The inhibiting efficiency of formed films was evaluated by various electrochemical techniques in 0.1 N Na2SO4 and NaCl solutions at 25°C. After one hour of immersion, films formed with all the tested compounds showed protective characteristics in the following sequence: OctS > PropS-MA > PropS > Bis-TMPA > BTES. EIS evidenced that the inhibitive properties of film decreased by increasing the immersion time in the aggressive solutions.
PROTECTIVE TREATMENTS OF A MAGNESIUM ALLOY WITH SILANES
ZUCCHI, Fabrizio;TRABANELLI, Giordano;GRASSI, Vincenzo;FRIGNANI, Alessandro
2001
Abstract
The protective characteristics of films formed on the AM60 magnesium alloy by treatments with trimethoxysilanes have been studied. The following silanes were examined: n-propyltrimethoxysilane (PropS), n-octyiltrimethoxysilane (OctS), 1,2-bis-trioxymethylsilylethane (BTES), bis-3(trimethoxysilyl)propylamine (Bis-TMPA), metaacryloxypropyltrimethoxysilane (PropS-MA) . The Mg alloy was treated in aqueous solutions of various silanes at 80°C. The influence of silane concentration, pH of the solution, time of immersion, time of hydrolysis, curing time at 100°C at the end of treatment was examined. The inhibiting efficiency of formed films was evaluated by various electrochemical techniques in 0.1 N Na2SO4 and NaCl solutions at 25°C. After one hour of immersion, films formed with all the tested compounds showed protective characteristics in the following sequence: OctS > PropS-MA > PropS > Bis-TMPA > BTES. EIS evidenced that the inhibitive properties of film decreased by increasing the immersion time in the aggressive solutions.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
