Company claims piston ring will help automotive industry lower emissions

Materials World magazine
9 Aug 2017

A new metal-silicide-strengthened bronze alloy could increase combustion engine efficiency.

A materials development specialist firm based in Cleveland, USA claims it is the first to use an innovative metal-silicide-strengthened bronze alloy for the creation of compression piston rings. Materion, which also has bases in countries across the world, found in tests that these piston rings could dramatically improve the efficiency of an internal combustion engine.

By 2020, car manufacturers selling vehicles in Europe must meet a fleet average emissions limit of 95g/km of CO2, with substantial punitive fines facing brands unable to comply. Many manufacturers are seeking to meet these targets by downsizing the internal combustion engines in their vehicles. To achieve similar performance as larger engines, smaller forced-induction engines must exhibit higher pressures and temperatures, which in turn can have a detrimental effect on component life and performance.










Materion claims that its ‘PerforMet’ piston rings allow car manufacturers greater efficiency and performance from downsized engines thanks to their very high levels of thermal conductivity – four times greater than that of traditional iron-based piston rings. As a result, heat is more effectively conducted into the engine block, where it can be dissipated by the cooling system.

Average piston temperatures can be reduced by up to 25°C, and piston crown temperatures by up to 30°C. This reduced average piston temperature increases fatigue resistance of the piston and combustion efficiency. It also reduces the risk of localised premature combustion – known as ‘knocking’ or ‘pinking’ – which further reduces engine efficiency and can cause engine damage. Mitigating this phenomenon could allow manufacturers to optimise combustion strategies, advancing the ignition timing to improve engine performance and efficiency.

Materion has supplied advanced alloy components such as valve guides, valve seats and bearings to race teams and engine customisation shops for close to 30 years. Many of these materials have been used in Formula 1, Le Mans, NASCAR and MotoGP.

The next phase of testing is already underway, evaluating PerforMet piston rings’ durability, longevity and wear characteristics in real-world internal combustion engines. These tests are being conducted in a single-cylinder motorcycle engine, while two high-volume global car manufacturers are planning to test PerforMet piston rings in multi-cylinder engines later in 2017.