Meaning
Thermomechanical process used to reverse the physical aging of a material and restore its youthful, higher-energy state. Structural rejuvenation typically involves applying high stress or rapid thermal cycling to increase the free volume and mobility within a glassy solid. This restoration improves the ductility and fracture toughness of materials that have become brittle over time.
Mechanical Reset
Plastic deformation through rolling or shot peening can drive a material away from its relaxed equilibrium state. In polymers, structural rejuvenation breaks the tight packing of molecular chains, allowing for easier movement under subsequent loads. This technique is often used to extend the service life of components that are susceptible to fatigue-induced hardening.
Processing Yield
Manufacturing operations benefit from the enhanced flow properties of a rejuvenated material. During a production run, structural rejuvenation can be achieved by heating the feedstock above the glass transition temperature before rapid cooling. This ensures that the final part has a consistent structure regardless of the age or storage history of the raw material.
Energy Threshold
Excessive energy input during the reset process can lead to thermal degradation or unwanted dimensional changes. The cost of calling it early is a part that remains too brittle for its intended application. Precision control of the rejuvenation cycle is necessary to balance the gain in toughness against the risk of structural damage.
