It has been investigated the possibility to decrease the corrosion rate in neutral salt solutions of two Mg based MMCs (AZ80A and ZK60A MMC) by silane treatment. Only a silane molecule with a long aliphatic chain (e.g. n-octadecyltrimethoxysilane, OctadecS) forms very protective layers, whose efficiency and persistency can be markedly increased by proper pre-treatments (i.e. Cerium sulphate solution and HF pickling). In the case of Ce(III) + OctadecS double treatment the anodic process is almost blocked. The pre-treatments, by alone, do not produce very positive results and their influence depends on the composition of the matrix. In the case of Zn and Zr rich Mg matrix (ZK60A MMC), HF pickling leads to the formation of an incoherent, powder layer.
Protective treatments of Mg metal matrix composites
ZUCCHI, Fabrizio;GRASSI, Vincenzo;FRIGNANI, Alessandro;TRABANELLI, Giordano
2004
Abstract
It has been investigated the possibility to decrease the corrosion rate in neutral salt solutions of two Mg based MMCs (AZ80A and ZK60A MMC) by silane treatment. Only a silane molecule with a long aliphatic chain (e.g. n-octadecyltrimethoxysilane, OctadecS) forms very protective layers, whose efficiency and persistency can be markedly increased by proper pre-treatments (i.e. Cerium sulphate solution and HF pickling). In the case of Ce(III) + OctadecS double treatment the anodic process is almost blocked. The pre-treatments, by alone, do not produce very positive results and their influence depends on the composition of the matrix. In the case of Zn and Zr rich Mg matrix (ZK60A MMC), HF pickling leads to the formation of an incoherent, powder layer.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
