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Author Tillmann, W. ♦ Nebel, J. ♦ Piotrowski, W.
Source SpringerLink
Content type Text
Publisher Springer US
File Format PDF
Copyright Year ©2012
Language English
Subject Domain (in DDC) Technology ♦ Engineering & allied operations
Subject Keyword CFD-modeling ♦ coating properties ♦ in-flight particle behavior ♦ substrate interaction ♦ Surfaces and Interfaces, Thin Films ♦ Tribology, Corrosion and Coatings ♦ Characterization and Evaluation of Materials ♦ Operating Procedures, Materials Treatment ♦ Analytical Chemistry
Abstract The use of fine feedstock powder can extend the feasibility and scope of HVOF coatings to new fields of applications. Especially for the purpose of near-net-shape coatings, these powders facilitate homogeneous layer morphologies, and smooth coating surfaces. However, the small particle sizes also lead to several challenges. One major issue is the in-flight behavior which is distinctly affected by the low mass and relatively large specific surface of the particles. In this paper, the in-flight and coating characteristics of WC-CoCr 86-10-4 (−10 + 2 μm) were investigated. It was determined that the fine powder feedstock shows a high sensitivity to the gas flow, velocity, and temperature of the spray jet. Because of their low mass inertia, their velocity, for example, is actually influenced by local pressure nodes (shock diamonds) in the supersonic flow. Additionally, the relatively large specific surface of the particles promotes partial overheating and degradation. Nevertheless, the morphological and mechanical properties of the sprayed layer are hardly affected. In fact, the coatings feature a superior surface roughness, porosity, hardness, and wear resistance.
ISSN 10599630
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2012-11-10
Publisher Place Boston
e-ISSN 15441016
Journal Journal of Thermal Spray Technology
Volume Number 22
Issue Number 2-3
Page Count 8
Starting Page 242
Ending Page 249


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Source: SpringerLink