Abstract
Key words:
Aluminum cylinder bore; Thermal sprayed coating; Endurance test; Pull-off test; Oil consumption
Abstract
This paper explores the issues related to the use of thermal sprayed coatings to protect aluminum cylinder bore against wear, stick slip and scuffing. The application of such coatings to high-performance sparkignition engines involves new aspects in the design process, as well as the development of alternative substrate treatment and surface machining. In order optimize the coating properties, the company Weber Motor AG has adopted various investigation tools, as surface/form analyses, observations on the metallographic structure, pull-off tests for the adhesion and tribology/endurance tests. Three different types of thermal coating techniques have been tested. The first results reveal positive behavior in terms of performances constancy, wear life extension and limited friction. The positive expectations about the oil consumption of engines provided with thermal sprayed cylinder bores have been met. These results, combined with considerations regarding process feasibility, furnish preliminary indications about the possibility to implement thermal sprayed coatings in series production.