Influence of Post-treatment on the Microstructural and Tribomechanical Properties of Suspension Thermally Sprayed WC–12 wt%Co Nanocomposite Coatings
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- 作者：O. Ali ; R. Ahmed ; N. H. Faisal ; Nayef M. Alanazi ; L.-M. Berger…
- 关键词：Nanostructured coating ; Sliding wear ; WC–12Co coating ; Suspension spraying ; Hot isostatic pressuring (HIPing) ; Microstructure ; Phase composition ; Wear mechanism ; Tribology
- 刊名：Tribology Letters
- 出版年：2017
- 出版时间：June 2017
- 年：2017
- 卷：65
- 期：2
- 全文大小：13210KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Tribology, Corrosion and Coatings; Surfaces and Interfaces, Thin Films; Theoretical and Applied Mechanics; Physical Chemistry; Nanotechnology;
- 出版者：Springer US
- ISSN：1573-2711
- 卷排序：65
文摘
The potential to improve the tribomechanical performance of HVOF-sprayed WC–12Co coatings was studied by using aqueous WC–12Co suspensions as feedstock. Both as-sprayed and hot-isostatic-pressed (HIPed) coatings were studied. Mathematical models of wear rate based on the structure property relationships, even for the conventionally sprayed WC–Co hardmetal coatings, are at best based on the semiempirical approach. This paper aims to develop these semiempirical mathematical models for suspension sprayed nanocomposite coatings in as-sprayed and heat-treated (HIPed) conditions. Microstructural evaluations included transmission electron microscopy, X-ray diffraction and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. The nanohardness and modulus of the coated specimens were investigated using a diamond Berkovich nanoindenter. Sliding wear tests were conducted using a ball-on-flat test rig. Results indicated that the HIPing post-treatment resulted in crystallization of amorphous coating phases and increase in elastic modulus and hardness. Influence of these changes in the wear mechanisms and wear rate is discussed. Results are also compared with conventionally sprayed high-velocity oxy-fuel hardmetal WC–Co coatings.