Solid-State.Phase.Transformations

Solid-state.phase.transformations.play.an.important.role.in.the.development.of.the. structure.and.properties.of.metals.and.alloys..Polymorphic.transformations.and.precipitation.reactions.are.the.main.types.of.phase.transformations.that.occur.in.solids.. Well-known.examples.are. the.polymorphic. transformations.of. iron,. titanium,.and. cobalt;.the.hardening.of.materials.by.martensitic.transformations;.and.the.strengthening.(dispersion.hardening).by.solid-state.precipitation..The.driving.force.behind. all.structural.and.phase.transformations.from.their.start.to.their.completion.at.a.given. temperature.and.pressure.is.the.decrease.of.the.Gibbs.free.energy..The.knowledge.of. phase.transformation.mechanisms.provides.the.basis.for.the.theory.and.practice.of. the.heat.treatment.and.the.processing.of.metals.