Topic: Pitting of 6061?
Hi. Just joined the forum today. My company manufactures 6061 components for the outdoor sports insutry. 100 % need to be anodized. We have recently run into a pitting issue on numerous components. All are machined and then wet tumbled (mass finnished) with a slightly alkaline burnishing compound and plastic media.
From there we use an ultrasonic cleaner and another slightly alkaline cleaning solution to remove any residue resulting from the mass finnishing. The parts are then put into a drying oven (200 degree F max). We then send out these parts to be anodized. Type two decorative in a variety of colors.
Our problem is that on any given batch of parts coming back from our anodizers( we have multiple) there is a white crystaline growth and pitting.
We use both import and domestic stock.Either solid, drawn, or extruded. All is 6061-t6 and approximatley one inch diameter. This has been a never ending nightmare of ours for a few years now.
Any one have a suggestion on were to look or start? This issue comes and goes. It is not confined to one specific part or color anodize. We think it may be a stock issue. Can there be such a difference in alloy compostion from batch to batch or supplier to supplier?
Last edited by rec (04/03/2009 - 06:47 PM)