21-Mat-A4 Deformation Behaviour and Properties of Materials, May 2014: worked solutions

Paper format. National Exams, May 2014 — 10-Met-A4, Structure of Materials. Three hours, closed book, one approved calculator (Casio or Sharp). Eight questions of 20 marks each; the rubric asks for any five, and only the first five in the answer book are marked. All eight are solved here, because this set is a study resource rather than an exam script. All necessary equations, constants and the error-function table are provided in the exam's own appendix and are used directly below.

Note on the exam title. The printed exam header reads 10-Met-A4, Structure of Materials. Only two of the eight questions (VI and VIII) are substantially deformation/mechanical-properties content; the paper as a whole is a broad introductory materials-science survey — bonding, crystallography, polymers, diffusion, XRD, phase diagrams, dislocations — and is answered as such below.

Check — figure-read values. Question VI.3's stress-strain curve and Question VII's Cu–Ag solvus/liquidus positions are read from the printed figures rather than given numerically. Graphically-read values carry a few percent uncertainty that closed-form calculations do not — this is flagged again at the point of use.

Reference texts. The answers below are keyed to the works normally recommended for this syllabus code:

W. D. Callister and D. G. Rethwisch, Materials Science and Engineering: An Introduction, 10th ed. — atomic bonding, crystal structure, imperfections, polymers, diffusion, mechanical properties, dislocations, XRD, phase diagrams.
G. E. Dieter, Mechanical Metallurgy, 3rd ed. — critical resolved shear stress, Schmid's law, strengthening mechanisms.

21-Mat-A4 Deformation Behaviour and Properties of Materials: May 2014