Materials
Metallurgy
5 self-contained study topics — notes, diagrams, formulas, and worked examples for exams and GATE.
Topics
- Iron Carbon EquilibriumThe iron-carbon diagram maps steel and cast-iron phases; cementite (Fe₃C) contains 6.67 % C and is hard and brittle. Steels (<2.14 % C) and cast irons (>2.14 % C) are distinguished by the eutectic composition, per physical-metallurgy texts.
- Ferrous and Non Ferrous AlloysFerrous alloys (steels, cast irons) are iron-based; weldability is judged by carbon equivalent CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15. Non-ferrous alloys (Al, Cu, Ti) offer lightness or corrosion resistance, per physical-metallurgy texts.
- Extraction of MetalsMetals are won from ores by reduction; feasibility is judged from the Ellingham diagram (ΔG° = −nFE° / ΔG° vs T). Pyrometallurgy, hydrometallurgy, and electrometallurgy suit different metals, per extractive-metallurgy texts.
- Heat Treatment CyclesHeat-treatment cycles specify austenitising temperature, soak time, and cooling medium: austenitise ~30–50 °C above A₃ (hypoeutectoid) or A₁ (hypereutectoid), then anneal, normalise, quench, or temper, per physical-metallurgy texts.
- Failure AnalysisFailure analysis identifies why a part failed — overload, fatigue, creep, corrosion, or wear. Fatigue-crack growth follows the Paris law da/dN = C(ΔK)^m; fractography reveals the mechanism, per failure-analysis texts.