The lead-tin phase diagram and the inverse lever rule

What this note covers

1. A binary phase diagram maps equilibrium states
2. Follow a cooling path through liquid and two-phase regions
3. The eutectic reaction forms two solid phases from liquid
4. Derive the inverse lever rule from mass balance
5. Convert fractions to masses and distinguish solubility models
6. Explain what the diagram establishes and what it does not
7. Worked inverse lever rule: phase fractions and phase masses
8. Worked diagram diagnosis: bulk composition cannot equal both phases

8 sections · 10 key terms & formulas · 6 common mistakes