A review on nanostructured WC-Co coatings

Unique mechanical properties of nanostructured materials motivate a worldwide interest to synthesize nailostructured coatings. Nanostructured WC-Co coatings have been extensively investigated because of the importance of WC-Co coatings in industrial applications, usually with respect to wear resistance requirements. The present paper has reviewed the studies in this field, including synthesis of nanostructured WC-Co powder, concern on decomposition of nanostructured WC particles, influence of spraying parameters on microstructure and mechanical properties of nanostructured coatings. Significant achievements in this field are: (1) It is possible to produce nanostructured WC-Co powders without tion-WC/Co phases in quantities although a high percentage of non-WC/Co phases is frequently reported in conventional WC-Co powder: (2) By controlling agglomerate size of feedstock powder. fuel chemistry and fuel-oxygen ratio. the decomposition of WC particles can be reasonably eliminated so as to synthesize near nanostructured WC-Co coating with a low amount of non-WC/Co phases: and (3) Increased hardness, toughness and wear-resistance can be obtained in near nanostructured WC-Co coatings that are properly synthesized. (C) 2002 Elsevier Science B.V. All rights reserved.