SMARTAQUA: Acting fast on marine corrosion

Maintenance is not the sexiest aspect of business, but diligent corrosion monitoring in the oil, gas, and maritime industry could prevent massive environmental accidents. Inês Pimparel writes on behalf of AquaBioTech Group.
Inês Pimparel

The maritime industry is going through massive developments. Traditional oil and gas remain powerful, as does the shipping industry, but there is a big rise in more sustainable businesses such as offshore wind and solar energy farms. Corrosion affects them all equally.

The NACE International Institute estimates that corrosion costs the maritime industry between $50 and $80 billion every year. Clearly, maintenance is an expensive practice, which might lead to neglect, resulting in catastrophic environmental incidents. 

A low-cost, eco-friendly, and efficient solution is needed to monitor corrosion and enable earlier repair.

The industry currently monitors structures using ultrasonic or magnetic sensors. However, other solutions exist. The University of Aveiro (Portugal), the Norwegian research institute SINTEF, and the Maltese company AquaBioTech Group are working on SMARTAQUA, an innovative but simple approach that uses a special paint. 

Scanning electron microscope pictures of nanomaterials used in the project.

It uses environmentally-friendly nanomaterials to form a functional solid film over surfaces such as the support for a floating fish farm or the base of a wind turbine. Because the nanolayer goes directly onto the structure, it can combine colorimetric with magnetic analysis to detect corrosion as it happens. 

The detection method will be tailor-made to the depth at which the metallic structure is placed to assess the integrity of the structures. Colorimetric detection is a relatively simple, user friendly, and reliable manner of detecting corrosion in splash zones. But in submerged structures, where colorimetric detection is not possible, the use of magnetic measurements would reveal the state of coated substrates.

The approach is not completely novel. The aeronautical sector is already introducing it. The AquaBioTech Group is performing toxicity tests on the nanomaterials using marine organisms such as microalgae and mussels. After this, the team will test the nanolayer’s efficacy on metallic structures in their offshore testing site close to St Paul’s Islands.

If this technology is proven safe and effective it will revolutionise the field of monitoring activities. It will reduce transport needs when assembling new offshore structures, indirectly reducing fuel use and greenhouse gas emissions. The commercial and environmental benefits are massive.

The project is highly collaborative. It brings together a small business, a research institute, and a university; testament that success can be achieved through co-creation, inclusivity, and sustainability—and that small advances can lead to a sea of change. 

Note: This project was funded by the Research Council of Norway (through the programme of Petromaks II, project 284002), the Foundation of Science and Technology in Portugal, and the Malta Council for Science and Technology via the MarTERA – ERA-NET Co-fund scheme of H2020 of the European Commission.

Thin Coatings For Better Hips

By the year 2030, due to the rise in age-expectancy and accompanying increase in frequency in bone-weakening conditions, total hip replacement surgeries will increase by 174%. One of the most important facets of implant surgery is biocompatibility. Durable implants that are biocompatible with human tissue are needed to prevent rejection and failure. And with this logarithmic expected rise, the need for longer lasting implants will be needed more than ever before.

Currently, metallic biomedical implants are the most common type. These, however, have a limited durability, often requiring surgery to be replaced after a decade. The combined action of wear and corrosion (termed tribocorrosion), brought about by friction during joint movements and the body’s aggressive environment, causes implant failure. A material called biomedical grade 316 LVM stainless steel is commonly used in hip-joint implants. It naturally forms a thin oxide film on its surface that protects the material from the body’s hostile environment. The problem with stainless steels is that despite this natural coat, tribocorrosion processes at the joints still form debris leading to problems for the patient and implant failure. Such failure can cause severe pain and expense when the hip implant needs to be replaced.

Antonino Mazzonello (supervised by Dr Ing. Bertram Mallia and Dr Ing. Joseph Buhagiar), is investigating a new type of coating on hip implants. He is analysing the corrosion-wear performance of a dual-layer coating made up of a Chrome-Nitride (Cr-N) layer followed by a Cobalt-Chrome-Molybdenum-Carbide (Co-Cr-Mo-C) layer deposited on top of low-temperature carburised stainless steel (the coatings are made by Prof. Peter Dearnely [Boride Services Ltd.]. This treatment is owned and carried out by Bodycote Plc. The top layer reduces friction while the bottom layer toughens the coating, reducing its removal. When the dual-layered stainless steel is compared to the untreated steel, the treated material is more resistant to wear and corrosion.

This new dual-coated material promises to be an ideal candidate for hip joint implants. Apart from being harder and more resistant, its low friction means that less effort would be required to move the joint. The encouraging results mean that in the near future this technology could be implemented in clinics. Mallia points out that ‘such multi-layered coatings may offer a giant step in increased durability for a relatively small additional expense.’

 This research is being performed as part of a Master’s degree in Mechanical Engineering, which Antonino Mazzonello is reading at the Faculty of Engineering, University of Malta. The research is supported by an Endeavour Scholarship. This scholarship is part-financed by the European Union; European Social Fund under Operational Programme II (ESF) 2014-2020, “Investigating in human capital to create more opportunities and promote the wellbeing of society”.
by Antonino Mazzonello