(a) In the shaping process of powder produced materials, the size of the particles is an important characteristic. Name two other characteristics of particles which are of significance and describe how these characteristics affect the material.
(b) What factors determine particle size in metal powder production by chemical reaction?
(c) One method of determining particle sizes is to measure the velocity of descent when the particles are suspended in a fluid.
(i) Describe two other methods.
(ii) An experiment to determine ceramic particle sizes showed that the rate of descent when suspended in a fluid ranged from 1.2 × 10–6m s–1 to 5 × 10–6 m s–1.
The density of the material was 3800 kg m–3 and the density and viscosity of the fluid at room temperature were 1632 kg m–3 and 0.00972 Pas respectively. Calculate the range of sizes of the particles.