Question

a) Which casting process would you recommend for the manufacture of an internal combustion engine block and why? Explain briefly the process that you have selected. b) Pure aluminium around

700°C is being poured into a sand casting mould. The metal level at the top of the sprue (pouring basin) is 32cm above the mould cavity. A circular runner connects the end of the sprue with the mould cavity. i) Assuming that the velocity of liquid metal at the top of the sprue (pouring basin) is zero,what is the velocity of the metal at the bottom of the sprue? ii) What runner diameter is needed to ensure aReynolds number of 2000? You should assume constant pressure in the sprue and no significant friction. Pure aluminum has a density of 2700 kg/m3 and a viscosity of 0.0015 Ns/m? around 700°C. \text { Bernoulli equation } \frac{u^{2}}{2 g}+\frac{p}{g \rho}+h=\text { constant } \text { Reynolds number Re }=\frac{\rho u D}{\mu} c) Explain with the aid of a schematic the electroplating process of nickel onto copper.What are the benefits of coating copper objects with nickel?

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