Hot air: metal replacement very close to the engine

Thanks to this stabilization, the Ultramid Endure retains its high strength in fatigue tests at 220 degrees Celsius even after 3000 hours, while considerable declines appear after a relatively short period of time in PA 66/6 and in even stronger thermoplastics such as PPA.

In addition to the effect of aging, material properties at the continuous operating temperature play a decisive role when designing a part. The toughness and strength values are especially important. If they are high enough, wall thickness can be reduced without endangering part integrity. The Ultramid Endure also performs exceptionally well in this regard. Its break stress at 200 degrees Celsius lies considerably above that of comparable products.

In addition to the performance of a part, system costs are an important criterion for developers. They are determined to a large extent by the processability of the material used. The new plastic offers problem-free processing with a noticeably wider processing window than other high-performance plastics.

As a result of the trend towards higher energy efficiency in automobiles, engine compartment temperatures continue to rise. For instance, automakers today are attempting to improve energy efficiency through turbocharging, among other approaches.

Turbocharging, i.e. increasing air intake, allows the performance of the engine to be shifted to an operating point characterized by better fuel consumption. This requires use of turbochargers, which generate higher pressures and temperatures in the engine compartment, especially in the charge-air duct. In turbocharged diesel engines, for instance, operating temperatures up to 200 degrees Celsius are common in the region between the turbocharger and intercooler and can spike to 230 degrees Celsius.

At the same time, automakers would like to replace metal with plastic for weight reasons, and at the lowest possible cost. Until now, there were no acceptable alternatives (from the standpoint of costs) to the considerably more expensive high-performance resins in this temperature range. The Ultramid Endure, with its exceptionally good heat aging behavior and good processability, now fills this gap and will raise the amount of plastic used in the charge-air duct of diesel engines significantly.

Possible applications include all components of the charge-air duct such as intercooler end caps, resonators, charge-air lines and throttle valves as well as components on the somewhat cooler side of the turbocharger. Intake manifolds with integrated water-cooled intercoolers could be an additional future application for the new material. The high temperatures associated with these special intake manifolds push classical intake manifold materials (PA 6) to their limits.