12th International Conference on the Mechanical Behavior on of Materials: Thermal Stability of Residual Streses in Ti-6Al-4V components

Research output: Contribution to conferenceAbstract

External Organisational units

  • Böhler Schmiedetechnik GmbH and Co KG
  • Materials Center Leoben Forschungs GmbH

Abstract

The need for light weight design while maintaining a high safety is essential for many components, especially in the aircraft industry. Therefore, it’s of utmost importance to consider every aspect to reduce weight, improve fatigue life and maintain safety of crucial components. Residual stresses are an important factor which can positively influence components and fulfil all three requirements. However, due to the inconstancy of the behaviour of residual stresses during the life time of a component, residual stresses are often neglected.
If the behaviour of residual stresses could be described reliably over the entire life time of a component, residual stresses could be taken into account and components could be optimized even further. Mechanical and thermal loads are the main reason for relaxation of residual stresses.
This work covers the thermal stability of residual stresses in Ti-6Al-4V components. Therefore, exposure tests at raised temperatures were performed on specimens with different surface conditions. The residual stresses were measured by x-ray diffraction before and after testing. Creep tests were also carried out to describe the creep behaviour and thereby the ability for residual stress relaxation. A correlation between the creep rate and amount of relaxed stress was found.
The creep behaviour of the material was described by using a combination of the Norton Power law and the Arrhenius equation. The Zener-Wert-Avrami model was used to describe the residual stress relaxation. With these models a satisfying correlation between measured and calculated data was found. Hence, the relaxation of residual stresses due to thermal load was described reliably.

Details

Original languageEnglish
Publication statusPublished - 10 May 2015
Event12th International Conference on the Mechanical Behavior of Materials ICM 12 - Karlsruhe , Germany
Duration: 10 May 201514 May 2015

Conference

Conference12th International Conference on the Mechanical Behavior of Materials ICM 12
Country/TerritoryGermany
CityKarlsruhe
Period10/05/1514/05/15