TAGS: Sustainability / Natural Coatings
RMIT Europe has been awarded AU$434K to contribute to ALCOAT, a research project developing aluminum alloy coatings as a more sustainable alternative to zinc galvanization.
Protection against corrosion is necessary to lengthen the service life of steel products and ensure the fulfilment of safety requirements by averting material failure.
Protection of Steel Structures
Steel is the world’s most important metallic construction material. Its mechanical properties, availability and affordability make it a staple in many building and infrastructure projects. Left untreated, steel is susceptible to oxidation and subsequent deterioration, with tell-tale signs of damage such as cracking and rusting especially prevalent in moisture-rich environments.
ALCOAT is a 42-month project that will develop two new families of aluminum alloy coatings, financed by the EU Research Fund for Coal & Steel (RFCS).
Recycled aluminum alloy coatings with chemically tailored electrochemical potential for safe protection of steel structures (ALCOAT) will recycle aluminum destined for landfill to create an alternative to zinc for the galvanization of steel products.
“
Scrap aluminum is widely available but being contaminated with iron and magnesium makes it brittle and unusable for many applications, meaning it is often either discarded or used for lower-level purposes such as pellets,” said Professor Ivan Cole, research director at RMIT Europe.
“
However, this aluminum is exactly what we need to produce a good coating for steel as the contaminants it contains actually stop oxide from forming,” continued Cole.
Reusing Existing Scrap Materials
This strategy of reusing existing scrap materials is one of the advantages of the project, while zinc continues to be widely used to protect steel from corrosion and is highly effective, it is also difficult to recycle.
“
ALCOAT will address a sustainability issue rather than a performance problem. Using existing scrap materials will prevent the energy-intensive process of mining and processing virgin zinc and the associated negative costs to the environment,” stated Cole.
The ALCOAT coatings will be used in the protection of wind towers, ships and other structures exposed to sea water and atmosphere as well as steel sheet products for automotive, building and home appliance industries.
Cost Reduction
“
Compared to traditional coating development processes, the procedure proposed by ALCOAT is highly innovative and advanced and will ensure a dramatic shortening of the development process and reduce costs,” added said.
The aluminum alloy coatings developed by the project are expected to have several advantages, such as a lower corrosion rate and a reduced risk of hydrogen embrittlement, which can occur with zinc coatings of high strength steels.
They will also be lighter, thinner and more sustainable given the reduction in the quantity of primary raw materials required, thereby also boosting efforts in the circular economy. It is expected that ALCOAT will contribute to improvements in the safety of steel constructions and provide a powerful tool to enhance other metal coating systems for material protection.
Source: RMIT University