Materials
Material Science
5 self-contained study topics — notes, diagrams, formulas, and worked examples for exams and GATE.
Topics
- Crystal Structure and DefectsCrystals pack atoms in lattices; the atomic packing factor APF = (n·v_atom)/V_cell is 0.68 for BCC and 0.74 for FCC. Point, line (dislocation), and planar defects control mechanical behaviour, per material-science texts.
- Phase Diagram BasicsA phase diagram maps stable phases versus composition and temperature; the lever rule gives phase fractions, e.g. W_α = (C₀ − C_L)/(C_α − C_L). Tie lines and the phase rule interpret two-phase regions, per material-science texts.
- Heat Treatment of SteelsHeat treatment controls steel microstructure by heating to austenite then cooling at a chosen rate. Hardenability is measured by the Jominy end-quench test; slow cooling gives pearlite, fast cooling gives martensite, per material-science texts.
- Mechanical TestingTensile testing gives engineering stress σ = P/A₀ and strain, from which yield strength, UTS, and ductility are read. Hardness, impact, fatigue, and creep tests characterise other behaviours, per material-science texts.
- Corrosion and PreventionCorrosion is electrochemical metal loss; the rate (mpy) = (K·W)/(A·T·ρ). Protection uses coatings, cathodic protection, inhibitors, and alloy selection, per material-science texts.