flow stress
Flow stress indicates the amount of stress needed to continue a metal's plastic deformation after it exceeds a yield. When metal is above yield, it can no longer randomly return to its original shape and begins losing its shape permanently. Continued strain will increase flow stress, which is the metal's ability to resist further deformation without additional applied strain.
Key Features:
- Strain-dependent behavior: As the deformation of the metal continues, dislocation density increases; this increases resistance and flow stress, known work hardening.
- Material-dependent: The flow stress varies depending on the type of material based on things like its composition, microstructure, and the temperature at which the deformation is undertaken.
- Forming metals: The flow stress of metals is critical to understanding creating products from metal. It is necessary to understand the flow stress of a metal when forming, because changing the formation - will change the effect it will have on the product quality.
Flow stress is essential for engineers and manufacturing companies when doing mechanical and manufacturing engineering on metal forming operations. Flow stress allows companies to scale products when predicting how a material will act when under stress. Companies can use flow stress to design tooling - machines that can shape components without mechanisms breaking down. Generally, flow stress decreases with higher temperatures, this is what hot working relies on to deform the metal.