Question:
a) In the shaping method of powder produced materials, the size of the particles is a significant characteristic. Name two other features of particles which are of importance and explain how these characteristics influence the material.
b) What factors determine the particle size in metal powder production by chemical reaction?
c) One method of finding out particle sizes is to measure the velocity of descent if the particles are suspended in a fluid.
Explain the two other methods.
An experiment to find out the ceramic particle sizes showed that the rate of descent whenever suspended in the fluid ranged from
1.2 × 10–6 m s–1 to 5 × 10–6 m s–1.
The density of material was 3800 kg m–3 and the density and viscosity of the fluid at room temperature were1632 kg m–3 and 0.00972 Pas respectively. Compute the range of sizes of the particles.