A magnetic solution cuts emissions

Truck maker Scania can now satisfy the EU’s new exhaust directive in a different way to competitors thanks to SEM’s skills and Höganäs’ SMC powder...

Scania has followed its own path towards satisfying new EU and US truck emission directives. Instead of cleaning exhaust emissions from engines using catalytic conversion, the company chose to build a new engine that uses fuel more efficiently, generating fewer emissions in the ignition process.

To succeed, a new approach and several new design features were necessary, especially in the fuel injection process. Scania developed a system in collaboration with one of the world’s leading truck engine manufacturers, Cummins of North America. Briefly, it injects fuel faster, more often and at higher pressure than before.

To achieve this, one precondition was the creation of a new type of stator, the component that opens the engine inlet valve. SEM in Sweden secured this assignment, and brought completely new qualities to a stator. They used Höganäs’ Somaloy SMC powder to attain the right magnetic characteristics.

“This is a very significant order for us”, said Andreas Johansson, SEM’s project manager, “We wouldn’t have got it if we have been unable to achieve the magnetic characteristics that Höganäs Somaloy makes possible.”

SEM’s collaboration with Burgess- Norton in the US, which presses the powder, was an important part of its success. Burgess-Norton has long experience of pressing magnetic powder, and has made substantial investments in developing the skills and tools for high-performance SMC powder components.

“Thanks to our collaboration with Höganäs, and their Somaloy powder, we can now press stator components with far higher densities than previously, and with extremely consistent quality. This gives them improved magnetic characteristics, so they respond to electrical impulses faster and more strongly. The result is better valve performance,” added Ted Baker, director of Soft Magnetics at Burgess-Norton.

Scania and Cummins also appear to be satisfied with the stator – after just a year, they doubled their order levels. The Euro 5 emissions directive came into effect in October 2009.

Somaloy Technology is the Soft Magnetic Composite (SMC) concept brand from Höganäs AB. The key concept is to produce components with 3D magnetic properties by pressing Somaloy powder to desired shape. Somaloy materials are composed of surface-insulated iron powder particles, which in one single step can be compacted to form components with complex shapes and tight tolerances.

Component manufacturing is based on the globally established, low cost PM-method. It is the 3D magnetic properties and the net shaping capabilities of Somaloy materials that open up new opportunities to design compact, light and cost-efficient solutions. Cost reduction can be obtained by reducing the total raw material cost as well as more efficient manufacturing and assembly. Somaloy technology meets future demands on efficiency, cost, performance and recyclability.