| USES |
Another example of Co. providing the enabling technology is that of the mould-making industry. Aluminium moulds coated with PEO have increased durability and better release properties than hard anodised moulds, without the high costs or forward planning associated with expensive steel moulds. As an immersion process, PEO can be used to coat the inner surfaces of even the most complex moulds. The PEO layer is attached to the substrate by means of a strong, atomic bond and components are released from the mould, time after time, without causing any damage. The PEO layer closest to the substrate is very hard and dense and provides excellent protection against corrosion and wear. Depending upon the alloy used and the thickness of the coating applied, PEO on aluminium can reach a hardness of 2,000 HV - at least three times harder than hard anodising, and in some cases, even harder than tool steel! Independent tests have shown that PEO is seven times more wear resistant than hard anodising and out-performs electroless nickel in ball-on-disk tests. When impregnated with PTFE, the wear performance of PEO can be even further enhanced. It is well known that aluminium moulds have a tendency to wear along the edges where conventional dip processes produce thinner layers of protection and where hard anodising has a tendency to crack, creating points of weakness. PEO overcomes this problem by producing a thicker layer of protection where it is most needed. In addition to this dense, protective layer, PEO has a thinner, porous, outer layer which lends itself well to impregnation with PTFE if required. With pores of around 1 micron in diameter, PEO can be immersed in or sprayed with PTFE to create a high quality non-stick surface. DuPont declared Co. a winner of the 2002 Plunkett Award for innovation with TeflonŽ for this very reason. |
|
Want more information ? Interested in the hidden information ? Click here and do your request. |