Exploring engine components to develop more durable, fuel-efficient lubricants

Neutron tomography performed on a piston at IMAT, allowing carbonaceous deposits on internal and external surfaces to be detected.​

Infineum UK Ltd and Finden Ltd, in collaboration, have taken advantage of the Science and Technology Facilities Council’s (STFC) ISIS Neutron and Muon Source to better understand organic deposits from lubricants in engine components.

The challenge

Engine components can over time develop ‘coke formations’ which can lead to increases in temperature causing cracking of components, blockages and engine failure. Coked components have poorer thermal conductivity, can reduce efficiency and the lifespan of engine components through increased wear, so lubricants not only act to reduce friction of such components but also play a key role in engine thermal management and cleanliness.

Both visual and X-ray imaging are often used to assess the performance of lubricating oils during engine testing and studying ‘carbon deposits’ which are the natural by-product of burning gasoline in gasoline engines. Although there are challenges regarding both of these methods, visual assessment can often mean vital information can be missed. In small objects, X-ray imaging is available to achieve the correct contrast between the low-density material and high-density substrate, but the large scale of engine components means that X-rays are strongly absorbed and inner surface deposits are often obscured. Assessing internal deposits are currently left to destructive methods, as often the component must be cut open and damaged therefore preventing continued use.

The experiment

A team of scientists from Infineum and Finden conducted this project at the ISIS Neutron and Muon Source, which operates a neutron imaging instrument for a broad range of material sciences. The high penetration of neutrons allowed for the lighter carbonaceous deposits found in large engine components to be clearly imaged on both external and internal surfaces. The deposits could also be quantified, in terms of: thickness, volume and areas covered. The facilities at STFC solved the challenges their industry faced with other methods of assessments, including visual and X-ray imaging.

The solution

By accessing STFC facilities, Infineum and Finden can now quantify where and when coking occurs within engines. The same component can be reviewed before, during and after an engine test therefore identifying how this is affected by different conditions and lubricants. STFC’s unique facilities and expertise supported this project and the better understanding of this challenge will help develop more durable, fuel efficient lubricants.

From this project a positive relationship between Finden, Infineum and STFC has been built. In particular, with Finden which was inexperienced in the application of neutrons before engaging with STFC. A long term collaboration between STFC and Finden has now progressed as Finden has improved familiarity with the capabilities of STFC technology and facilities.

“Accessing STFC’s Neutron and Muon Source, allowed us to overcome a significant challenge within our industry. We were unaware of the benefits of neutrons before STFC engaged with us. Without the unique facilities and expertise provided by STFC the completion of this project would not have been possible. After this project we are now working closer with STFC and look forward to any further possibilities of collaborating again.”

Dr Stephen Price
Finden Ltd.