Wettability effect on the flattening ratio of molten metal droplets

Plasma sprayed coatings are formed by a continuous deposition of numerous a nd molten droplets, which lead to a lamella structure. So it is very crucia l to understand the interaction between molten droplets and substrates. Wet tability is one of the factors governing the interaction. This report prese nts the influence of wettability of substrates by molten metal droplets on the flattening degree of splats. Using a free-fall apparatus of droplets, t he metals, Sn, Pb, Cu and Fe are used for the experiments. Taking an equili brium contact angle of metals into the energy balance for impingement of mo lten droplets, the relationship between the theoretical and experimental re sults shows approximately a good agreement in some R-e and W-e regions. (C) 2001 Elsevier Science B.V. All rights reserved.