The PTWA thermal spray process utilizes a single wire as the feedstock material. The wire is melted, atomized and propelled to the substrate by a supersonic plasma jet that is formed by a transferred arc between a non-consumable cathode and the tip of the wire.

After initial atomization, a large flow of forced air through the nozzle transports the stream of molten droplets onto the bore wall. The high kinetic energy causes the particles to flatten when they impinge on the surface of the substrate; the heat transfer between the flattened particles and the substrate causes a rapid solidification. Thus the coating is made up of these solidified droplets stacked one on top of another along the surface.

Schematic diagram of PTWA system. Click to enlarge.

The surface is then honed into a piston-ready cylinder bore. The technology, which is used on high-performance cars such as the Mustang GT500 and the Nissan GT/R, improves heat transfer and reduces friction.

For Elio Motors, it is projected to boost engine performance by 10%, while reducing engine weight, helping Elio Motors achieve its 84 mpg (2.8 l/100 km) target.