If you attend a motorsport trade show and look at the pistons on offer, you will see that a number of them have a coating (or sometimes more than one coating). More often than not, where a single coating is applied to a piston, it will be a skirt coating. Piston skirt coatings are very commonly used, and the practice is not just a recent phenomenon. There are a number of reasons for the use of a coating on a piston skirt. The conclusion many people will jump to is that they are primarily...
Diamond-like coatings (known universally as DLC) are a type of coating that has really taken the racing world by storm. There are a whole range of coatings that come under the description of DLC, with varying levels of hardness and coefficient of friction. They are also very thin. They are not though something that can be applied without due thought to any situation that the designer feels may merit such a coating. The geometry of the part and the underlying material must also be...
In an article posted in February 2011 on the subject of coatings, there was a brief discussion of the physical vapour deposition (PVD) method, some of the coatings used in motorsport that are commonly associated with this method, and some of the pitfalls of blindly specifying the latest coating without taking account of the exact type and grade of material being coated. In this article, I'll look into the method in more depth. The method lends itself to a very wide variety of coating...
Many of the applications discussed in the RET-Monitor articles where thermal barrier coatings are concerned have been on the subject of exhausts. Thermal barrier coatings here have the aim of reducing radiated heat, although in some cases a benefit of such coatings can be to improve the efficiency of the turbocharger turbine by retaining heat within the exhaust flow rather than rejecting it to atmosphere prior to the turbine. There are other applications of thermal barrier coatings which...
The use of plasma-sprayed coatings has been slow to proliferate; the technique isn't very new, and the range of coatings is immense. Whereas other coating methods can be limited - by solubility of metal salts in electrolytes, for example - plasma coatings are generally limited only by the availability of material in the correct form and the ability of the coating material to be melted. There are a number of sprayed coating methods, distinguished not only by the particular method of...