### Material Science - short answer questions from AMIE exams

If G = 130 GPa for a metal and Poisson's ratio = 0.3, calc ulate the value of E for the metal. Modulus of elasticity (E) = 45 MPa, and Poisson's ratio (Î¼) = 0.31 The relation between Elastic modulus and Poisson's ratio and Modulus of rigidity is given as: E = 2G(1 + Î¼) ⇒ 130 = 2 × G (1 + 0.3) From this, G = 50 GPa Stainless steels (an alloy of iron, a = 0.2867 nm) always can contain a huge amount of chromium. (a = 0.2885 nm). Explain. From the given lattice parameters (a) the corresponding radii for iron and chromium are 0.124 nm. and 0.125 nm which are nearly the same so can easily form the crystal bonding. Stainless steel contains about up to 11% chromium. Define isomorphous systems with examples. The term isomorphous system is related to phase diagram, isomorphic means having the same crystal structure or complete solubility for all compositions. The copper-nickel system is an example of an isomorphous system. A pure copper wire has been drawn at a temperature of