strengthen metal Flashcards
What is Work Hardening (Strain Hardening)?
Process: Deforming the metal plastically at room temperature.
Mechanism: Dislocation density increases with deformation, and these dislocations interact and hinder further movement, increasing strength.
What is Grain Boundary Strengthening (Hall-Petch Effect)?
Process: Refining the grain size of the metal.
Mechanism: Grain boundaries act as barriers to dislocation motion. Smaller grains mean more grain boundaries, which impede dislocation movement.
What is Solid Solution Strengthening?
Process: Adding alloying elements to the base metal.
Mechanism: Solute atoms create lattice distortions that hinder dislocation movement.
What is Precipitation Hardening (Age Hardening)?
Process: Heating the alloy to a high temperature and then cooling it to form small, dispersed particles (precipitates).
Mechanism: Precipitates impede dislocation motion by creating obstacles within the crystal lattice.
What is Dispersion Strengthening?
Process: Introducing non-coherent second-phase particles within the metal matrix.
Mechanism: These particles impede dislocation motion more effectively than coherent precipitates.
What is Phase Transformation Strengthening (Martensitic Transformation)?
Process: Rapid cooling (quenching) from a high temperature to form martensite.
Mechanism: The martensitic structure is harder and stronger due to its tetragonal structure and high dislocation density.
What is Twin Boundary Strengthening?
Process: Forming twin boundaries within the crystal structure.
Mechanism: Twin boundaries act similarly to grain boundaries in impeding dislocation motion.
What is Fiber Reinforcement (in Composite Materials)?
Process: Embedding strong fibers within the metal matrix.
Mechanism: Fibers carry a portion of the load and hinder crack propagation.
