A materials system and method of its application for the wear protection of aluminiumengine cylinder bore surfaces

摘要

The application of wear resistant coatings onto the wall of aluminium engine cylinder bores by thermal spray haveseen much development over the last 10 years, with regards to both equipment design and also to the materialsystem used. While the technology has been successful in allowing the implementation of aluminium engineblocks into mass production, there is still room for improvement. One area that can be improved is the preparationof the substrate material in order to allow a good adhesion of the thermal spray coating. Grit blasting, a traditionalpreparation technique, is undesirable for a mass production environment due to the risk of the assembly areasbecoming contaminated with grit. Therefore, an alternative method has been sought that can offer a suitable bondstrength without introducing potential risks in the manufacture line. In this study, NiAl bond coats were sprayedonto aluminium substrates using the Plasma Transferred Wire Arc (PTWA) coating system developed by FordMotor Company. A variety of surface preparation techniques, including traditional and some more novel methods,were used and analysed with respect to bond strength, ease of application and cost.