Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exam 04-BS-11, Properties of Materials — May 2019 sitting (the cover page and every page footer read “04-BS-11, May2019”). 3 hours, closed-book examination (Casio/Sharp calculator only). Notes on the paper state that candidates are to attempt five, and only five, questions, with only the first five appearing in the answer book marked and all questions of equal value. All seven questions are solved below for completeness.
Reference texts: Callister & Rethwisch, Materials Science and Engineering: An Introduction, 9th ed. (crystal structure and Miller indices; tensile testing and true strain; hardness testing; solid solutions and grain size; phase diagrams and the lever rule; dislocations and cold work; polymer molecular weight and viscoelastic behaviour; TTT diagrams and heat treatment; fracture/fatigue).
Page-1 data used below: atomic masses (g/mol) H 1.01, C 12.01, Mo 95.94; $N_A=0.602\times10^{24}$ mol$^{-1}$; cold work $CW=(A_0-A_f)/A_0$; grain size $N=2^{n-1}$. Fig 1 (Al–Si diagram), Fig 2 (cold work vs. properties, iron and copper) and Fig 3 (isothermal diagram, 0.8% C steel) are printed in the paper; the values used below were read off them.
