Critical Issues for Chrome-free Pretreatment of Aluminium Alloys
Critical Issues for Chrome-free Pretreatment of Aluminium Alloys
Critical Issues for Chrome-free Pretreatment of Aluminium Alloys
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Critical</strong> <strong>Issues</strong> <strong>for</strong> <strong>Chrome</strong>-<strong>free</strong> <strong>Pretreatment</strong> <strong>of</strong> <strong>Aluminium</strong> <strong>Alloys</strong><br />
Activation <strong>of</strong> De<strong>for</strong>med Surface Layers<br />
• Promoted by preferential precipitation compared to the bulk due to<br />
enhanced diffusion<br />
• Most studies have concentrated on manganese. Activation level<br />
depends on time and temperature <strong>of</strong> heat treatment.<br />
• AA6xxx alloys are probably activated by preferential precipitation<br />
ageing precipitates during paint bake or by natural ageing<br />
• AA5xxx alloys can be activated by sensitisation treatments<br />
International Conference on Environmental friendly <strong>Pretreatment</strong>s fo <strong>Aluminium</strong> and other Metals, Oslo, Norway, June 16-18, 2004
Change language