When an engine fails or becomes very worn, it is usually pulled from the vehicle and scrapped. Ford wants to change that by utilizing a high-tech plasma process to remanufacture broken engines. The process reduces carbon emissions by about half when compared to making a new engine to replace the old one, and results in a like-new engine block.
The goal is to extend the performance of a vehicle by lengthening its lifespan, thus reducing its overall environmental footprint. It ties in with other research being done by Ford to include vegetable fibers in plastics and soy fibers in foam and cloth.
The process was originally developed for engine performance enhancement, says Juergen Wesemann, manager of Vehicle Technologies and Materials, Ford Research and Advanced Engineering. The Plasma Transferred Wired Arc (PTWA) thermal spray process applies a coat to an engine block which helps bring it back to original condition. This removes the need for additional heavy parts.
PTWA works by basically creating "paint" out of metallic materials. A wire feedstock is first fed into a highly-charged cathode. This atomizes the feedstock, which is then sprayed onto a surface with forced gas. The high kinetic energy of the particles means that they flatten on impact with the surface of the target. They then quickly harden. This has the effect of both depositing even amounts of material onto a surface and of "leveling" the surface by naturally filling in pits and gouges.
In most PTWA processes, varied materials will be used to build multi-layer coatings. When witnessed first hand, the plasma coating process looks similar to spray painting, but with a bright light where the paint emerges.
The plasma coating process itself is not new. It's been a key ingredient for making aluminum engine blocks that can withstand repeated pressure without a cast iron sleeve in the cylinder bores. In the automotive manufacturing process, PTWA has become a common element. High-end vehicles such as the Nissan GT-R and Ford Mustang GT500 Shelby utilize plasma coating to improve friction surfaces and reduce weights by adding strength to parts made of lighter-weight materials.
For remanufacturing, pioneering use of plasma coating began with Caterpillar and others in the diesel engine realm, using it to refurbish high-mileage or high-use engine blocks that would otherwise be very expensive to replace. PTWA can be used on cast iron, aluminum, or nearly any other metal or alloy.
The process for Ford is to take worn, high-mileage engines and use plasma coatings to refurbish and repair the engine block, especially the cylinders, as the first step towards creating a like-new engine that can be used again.
Source: Ford
