After five years of use exclusively in AMG engines, twin-wire arc spraying technology will now also be used in the series production of Mercedes-Benz diesel engines. Mercedes-Benz was the developer of what is now known as Nanoslide technology, in which twin-wire arc spraying is used to melt iron/carbon wires and spray them onto the cylinder surfaces of the lightweight aluminium crankcase with the help of a gasflow.
Very fine finishing of the resulting nano-crystalline iron coating creates an almost mirror-like, smooth surface with fine pores, which reduces friction and wear between the piston assembly and the cylinder wall. Other advantages include lower engine weight, less fuel consumption and lower emissions. This innovation from Mercedes-Benz has been successfully used in the 6.3-liter AMG engines since 2006.
Mercedes-Benz uses the collective term “Blue Efficiency” to describe a whole range of different measures designed to reduce fuel consumption and emissions: sophisticated aerodynamics, weight-saving measures and intelligent control of ancillary units are a few examples. With Nanoslide technology, the world’s oldest automobile manufacturer is adding another innovation to this technology package. It sets new standards in the production of cylinder linings. These help to ensure that the piston moves up and down within the cylinder with the least possible friction losses. Comparatively heavy grey cast-iron liners with a thickness of up to five millimeters are the current state of the art.
The Nanoslide procedure takes a new approach. Wires of iron/carbon alloy are melted in an electric arc, and the melted material is “sprayed” onto the cylinder wall by a gasflow, where it is deposited as a layered, ultra-fine to nano-crystalline coating. The Nanoslide coating is then given an extremely smooth finish by a special honing process, after which it has a thickness of only 0.1 to 0.15 millimeters and has a mirror-like surface. The honing process also exposes pores in the material which are able to retain oil and thereby ensure optimal lubrication of the piston assembly. The result is not only low friction, and therefore greatly reduced mechanical friction losses compared to grey cast-iron cylinder liners (up to 50 percent), but also extremely high wear resistance.