Single Droplet Formation for a Liquid SnBi Alloy

Title

Single Droplet Formation for a Liquid SnBi Alloy

 Author

Vos, M.

Contributor

Mudde, R.F. (mentor)
Van Heuven, J.W. (mentor)
Oud, M.A. (mentor)
Biglari, M.H. (mentor)

Faculty

Applied Sciences

 Department

Kramers Laboratorium voor Fysische Technologie

 Date

1998-08-01

 Abstract

A production process developed to produce tin-bismuth alloy shot particles directly out o f the liquid metal phase, appeared difficult to be controlled. Therefore, within this graduation project, the underlying physical principles o f droplet formation and the process parameters had to be characterised. After characterisation of the process parameters, the uniform production o f spherical particles had to be realised and controlled. A small scale experimental setup was used to test and realise these results. Periodic single droplet formation at the nozzle was demonstrated to be the most suitable mechanism for uniform shot production. A relation for the maximum uniform production rate was found and evaluated. Both the maximum production rate and the diameter of the produced shot are determined by the nozzle diameter, the metal flow rate through the nozzle, and the metal properties (surface tension and density). Oxidising gas components cause unstable droplet formation and non-spherical shapes. The viscosity of the coolant is determining for the end shape o f the shot particle.Tests with a high viscosity oil (also at elevated temperature) increased the sphericity of the shot particles. A maximum mean shot diameter of 3.3 mm was produced with a nozzle diameter o f 1.5 mm. The tin bismuth alloy showed non-wetting behaviour on the steel nozzle surface. The shape factor, defined as the ratio of the two longest lengths of an ellipsoidal particle, has been determined at 1.05. Uniform production of tin bismuth shot, directly out of the liquid metal phase is feasible, although it has been shown very sensitive to fluctuations in the operating conditions.

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 Part of collection

Student theses

 Document type

master thesis

 Rights

(c) 1998 Vos, M.
Files
PDF Vos_1998.pdf 21.52 MB
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