Effects of Re-Aging on the Fatigue Properties of Aluminum Alloy AA7075

Fakioglu A., ÖZYÜREK D.

MATERIALS TESTING, cilt.56, ss.575-582, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 56
  • Basım Tarihi: 2014
  • Doi Numarası: 10.3139/120.110598
  • Sayfa Sayıları: ss.575-582


In this study, 7075 aluminum alloy was subjected to triple-aging of retrogression and re-aging (RRA) treatments. The alloy was retrogressed at 220 degrees C for 60 minutes following the T6 heat treatment and later re-aged at temperatures between 100 degrees C and 140 degrees C for 24 hours and at 120 degrees C for various durations in the range of 15-35 hours. The effects of temperature and duration of re-aging on hardness and the fatigue behaviors of RRA tempered 7075 aluminum alloys were investigated. The results show that temperature and duration of re-aging have an influence on both hardness and fatigue resistances. An increment of the hardness values depends on increasing of re-aging temperature and times until 120 degrees C and 24 hours and reaches to the maximum value. However, those values decrease with higher re-aging temperatures and longer duration than 120 degrees C and 24 hours, respectively. On the other hand, in the fatigue tests, the highest fatigue resistance was observed for the sample re-aged at 120 degrees C for 24 hours, while the sample re-aged at 140 degrees C for 24 hours showed the longest fatigue life under lower fatigue stress.