The 0.15mm-thick coating will be used when producing the new Evo three-cylinder engines from the EA211 series of Volkswagen engines and will help to reduce internal friction.
As a result, the 1.0 TSI EVO turbocharged petrol engines will be even more efficient and boast even lower emissions.
The carmaker from the Czech Republic has invested almost 29mil euros in preparing, converting and upgrading its Mladá Boleslav-based headquarters.
The vehicles that will benefit from the plasma coating are the Octavia e-Tec mild-hybrids.
The Czech car manufacturer has added an assembly line with two special fixtures for plasma coating at its main plant and both of them include two torches.
Furthermore, the company also invested an additional 28.8mil euros in upgrading the plant in this way; overall, the carmaker spent 69.1mil euros to modernise its engine production line.
During the production process, the cylinders are first bored on the machining line.
A 1,500W laser then abrades the cylinder bores to ensure that the plasma layer will optimally adhere to the surface.
This involves the laser beam creating ten grooves per millimetre, each measuring an average depth of 0.04mm.
This production step takes place in a controlled atmosphere filled with nitrogen to keep the laser’s optics free from contamination and to ensure the necessary level of accuracy.
A mixture of hydrogen and argon is used to create plasma gas, requiring 4.5 litres of hydrogen per minute during the process.
The plasma reaches a temperature of 15,000 degrees Celsius and is then mixed with various types of elements (iron, carbon, silicon and manganese among others) that have been grounded into a fine powder with each grain no more 0.05mm.
When sprayed onto the cylinder walls, the molten powder forms a layer measuring approximately 0.25mm-thick.
During final processing, this layer is honed out, so that it measures just 0.150mm-thick compared to a conventional cylinder wall that's usually 4mm-thick.
Each cylinder is automatically measured at several stages throughout the process to assess its quality.
Optical measuring instruments first record the surface abraded by the laser before a second measurement is taken once the plasma has been applied.
Finally, the structure of the plasma layer is and then tested using turbulent flow.
“The technically highly innovative plasma coating makes our EA211 TSI EVO engines even more efficient. It reduces friction losses and thus also fuel consumption. What’s more, this type of coating also allows heat to be more evenly distributed within the cylinders and helps it to dissipate more efficiently, thus optimising the thermal load.
"We produce the plasma-coated engines at Mladá Boleslav in three shifts and are installing them in the Fabia, Scala, Octavia, Kamiq and Karoq,” said Škoda Auto component production head Christian Bleiel.
