Improved materials for durable rings, liners, and injector nozzles.

摘要

This state-of-technololy review for spray-deposited WC-Co wear-resistant coatings was done as part of the durability R&D task of the Coal-Fueled Disel Technology Development Contract (No. DE-AC21-88MC23174). An important objective of this contract is to optimize the material performance engine components. Preliminary studies had indicated that plasma-spray-deposited WC-Co coatings have excellent potential for protecting rings and cyclinders in the disel engine. This review includes a background summary and a survey of vendors and literature. It was concluded from the literature survey that considering the apparent widespread use of spray-deposited WC-Co coatings, it seems surprising that the information in the literature is so sparse. In particular, there is a lack of information that relates the properties of the coatings in their chemistry, microstructure, and morphology. The relationships between starting powder characteristics, deposition conditions, and properties also are generally obscure. An exception, to some extent, seems to be persuasive evidence that favors LPPD processing over APPD processing to improve properties. However, there is no evidence that LPPD processing is actually being used in the industry.