a) i) Explain the difference between cold and hot working in metals. ii) Define the re-crystallization temperature. iii) Explain why the material strength increases during cold working. b) Explain the

effects of the three stages of annealing i.e. recovery, recrystallisation and grain grown on the structure and properties of cold worked metal. c) During a tensile test, a metal has a true strain of 0.08 at a true stress of 2.32x108 Pa.Later, at a true stress of 3.91x108 Pa, the true strain is 0.22. Determine the flow curve parameters n and K. The relationship between true stress and true strain in the plastic region can be expressed as: \sigma_{\mathrm{T}}=K \varepsilon_{T}^{n} \text { where } \sigma_{T} \text { is the true stress and } \mathrm{ET} \text { is the true strain. }