C. Moreau, National Research Council Canada (CNRC-NRC), Boucherville,, QC, Canada; A. McDonald, University of Toronto, Toronto, ON, Canada; M. Lamontagne, Industrial Materials Institute, National Research Council Canada, Boucherville, QC, Canada; S. Chandra, Centre for Advanced Coating Technology, University of Toronto, Toronto, ON, Canada
Plasma-sprayed, molten molybdenum particles (~50 µm diameter) were photographed during impact (with velocity ~140 m/s) on metal surfaces that were maintained at room temperature. A droplet approaching the surface was sensed using a photodetector and after a known delay, an 11 ns light pulse was produced to illuminate the spreading splat. A CCD camera captured images of the spreading splat at different angles from the substrate front surface. A rapid two-color pyrometer was used to collect the thermal radiation from the impacting particles to follow the evolution of their temperature and size after impact. Molten molybdenum particles impacting on the surfaces at room temperature disintegrated and splashed, after achieving a maximum diameter larger than 300 µm.
Summary: Plasma-sprayed particles that impacted metal surfaces held at room temperature were photographed at different angles from the substrate front surface. Images of the spreading particles were captured at different times after impact. The resulting splats disintegrated and splashed after reaching a maximum diameter of approximately 300 µm.
