In as-quenched state, the damping capacity of Fe-17%Mn-X%C alloys is lower in higher carbon contents. This is associated with the decrease in quantity of damping sources such as stacking fault boundaries in ∈ martensite, ∈ martensite variant boundaries, and γ/∈ interfaces in response to the decrease in ∈ martensite volume fraction with increasing carbon content. When the alloys are aged up to 60 minutes in a range of 313 to 373K, the damping capacity decreases more rapidly with increasing temperature, and at a fixed temperature, it deteriorates with time. The average rate of decrease in damping capacity has a maximum value at 0.10% of carbon content regardless of aging temperature, because it depends both on the quantity of the boundaries acting as damping sources and on the segregated carbon content, simultaneously. The activation energy for the process of decrease in damping capacity is about 6Kcal/mol irrespective of carbon content. Such a small activation energy implies that the carbon segregation along the boundaries acting as damping sources may arise from stress-assisted carbon diffusion owing to vibration as well as interaction between carbon atoms and the boundaries.
Bibliographical noteFunding Information:
This work was performed by the Research Fund of POSCO Professor.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys