Materials chemistry

Alloys, chemical metallurgy

Explain how alloy composition, phases and processing determine properties, and connect extraction and refining reactions to thermodynamics and material selection.

1 Lower secondary 2 Upper secondary 3 Undergraduate 4 Advanced 5 Research

IntuitionMore than a mixture of metals

Compare a single-phase substitutional solid solution with a multiphase alloy; phases and interfaces change as composition and thermal history vary.

SchoolComposition and phase

Definition: Alloy

Example

Solution

wCu = 70/100 = 70%; wZn = 30/100 = 30%. These are mass fractions, not atomic percentages.

Common strengthening or service strategies
Approach	Mechanism or example
Solid-solution strengthening	Solute strain fields impede dislocations
Precipitation hardening	Fine precipitates obstruct slip
Passivation	Protective oxide film, e.g. stainless steel

UndergraduatePhase equilibria and extraction

References

Physical Metallurgy Principles, 4th Edition · R. E. Reed-Hill, R. Abbaschian, 2009