Isothermal transformation

Isothermal transformation diagrams (also known as time-temperature-transformation or TTT diagrams) are plots of temperature versus the logarithm of time, denoting the transformations of an austenitized alloy as it undergoes a heat treatment. Isothermal transformation diagrams are only valid for one specific composition of material, and only if the temperature is held constant during the transformation. Though usually used for alloys, they also can be used to describe the kinetics of crystallization in ceramic materials. Isothermal transformation diagrams are generated from percentage transformation-vs logarithm of time measurements.

See also

• Continuous cooling transformation

References

• Materials science and Engineering, an introduction. William D. Callister Jr, 7th Ed, Wiley and sons publishing. Pages 326, 462