Splat formation of molten Sn, Cu and Ni droplets

Plasma spraying and other deposition or coating techniques cause splat formation of the molten droplets. This paper presents Free falling and splat formation experiments in which molten droplets of Sn, Cu and Ni were impinged on the cooled substrate and solidified after the Battening process, The flattening ratio, defined as the flattening disc diameter to the droplet diameter, was measured under different conditions. The obtained results were different from the proposed theories, which neglect the solidifying effect. The flattening ratio experimentally obtained was proposed with respect to Re and We numbers, independently. The unevenness ratio was introduced and is defined by the contour length of the Battening disc to the circumferential length of an equivalent circle which has the same area as the flattening disc. This was measured with respect to Re and We numbers and represented an experimental formula of the unevenness ratio. It was concluded that the unevenness ratio was closely related to surface tension and impinging velocity, (C) 1997 Elsevier Science S.A.