Improving corrosion resistance of anodised aluminium die cast parts - by sealing in chromate bath followed by hot water bath

摘要

The corrosion resistance of anodised Al alloy part. esp. having high Si and/or Cn contents, is increased by sealing in a two stage process. The first stage takes place in a K2- or Na2Cr2O7 bath and after rinsing in a second hot water bath. USE/ADVANTAGE - Treating Al die cast alloy oxide layers, esp. those present in parts used for brake manufacture. The corrosion resistance after 240 hrs in a salt mixt. is good as no corrosion signs are visible.