Abstract No.:
2599

 Scheduled at:
Tuesday, September 27, 2011, Saal C2.2 4:25 PM
Characterization & Testing 2


 Title:
Particle size distribution of the filling powder in cored wires and its effect on arc behavior, in-flight particle behavior, and splat formation

 Authors:
Mohamed Abdulgader* / University of Dortmund, Germany
Wolfgang Tillmann / Institute of Materials Engineering , Germany

 Abstract:
The composition of the cored wires is inhomogeneous. It contains solid velum as well as a powder filling which strongly influences the particle formation, in-flight particle behavior, the coating microstructure, and consequently the behavior of the desired coating. To study the effect of particle size distribution of the filling powder in cored wires the parameters of the twin wire arc spraying process such as current, voltage, and atomization air pressure are varied for three intervals of particle size distributions (25-45µm, 45-63µm, and 63-90µm). Fluctuations in arc voltage and current are measured and found to be higher at small particle sizes. By using cored wires, with small particle sizes the particle velocity was higher, while the particle temperature is higher in case of big particle sizes. The splats tend to form a regular desk shape using cored wires with small particle sizes. Therefore, the lamellas are more homogenous and the porosity is lower than the coating produced by means of cored wires with big particle sizes. This investigation is important for deep understanding of twin wire arc spraying with cored wires.

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