Strengthening by dispersing fine particles, such as oxides that do not dissolve in the matrix, to hinder dislocation motion. The particles resist coarsening, so strength is retained at high temperature.
Japanese name: 分散強化
Dispersion strengthening appears in 1 practice question across 1 topic, including Strengthening mechanisms and dislocations.
Answer: B. Hard oxides that do not dissolve in the matrix and resist coarsening force dislocations to bypass them, so strength tends to remain even at high temperatures where precipitates dissolve or coarsen
In dispersion strengthening, oxide particles that hardly dissolve in or react with the matrix are produced and dispersed by internal oxidation or by mechanical alloying, in which powders are mixed intensely. Hard, incoherent particles are not sheared by dislocations and strengthen through the Orowan mechanism. Precipitates lose their strength at high temperature by dissolving or coarsening through Ostwald ripening, but oxide particles change little up to near the melting point, so strength and creep resistance at high temperature are retained. Al₂O₃-dispersed copper is used for welding electrodes and other parts that must resist softening at high temperature, and ODS steels are candidate materials for nuclear fuel cladding. The option about precipitating by aging describes precipitation hardening; oxides do not dissolve in the matrix, so they cannot be solution treated. Antiphase boundaries concern the shearing of ordered precipitates.
In dispersion strengthening, oxide particles that hardly dissolve in or react with the matrix are produced and dispersed by internal oxidation or by mechanical alloying, in which powders are mixed intensely.
Which statement about dispersion strengthening with oxide p…Dislocation Orowan mechanism Ostwald ripening Creep Precipitation hardening Bauschinger effect Critical resolved shear stress Peierls stress Schmid factor Taylor factor