Author/Authors :
Ershadi Khamneh، M. نويسنده Department of Materials Engineering, Tarbiat Modares University, Tehran, Iran. , , Shahverdi، H. R. نويسنده Tarbiat Modares University, Faculty of Engineering, Department of Materials Engineering, Tehran, Iran. , , Hadavi، S. M. M. نويسنده Department of Materials Engineering, Amir Kabir University of Technology, Tehran, Iran Hadavi, S. M. M.
Abstract :
Creep age forming (CAF) is one of the novel methods in aerospace industry that has been used to
manufacture components of panels with improved mechanical properties and reduced fabrication cost. CAF is a
combined age-hardening and stress-relaxation that are responsible for strengthening and forming, respectively. This
paper deals with the experimental investigations of mechanical and springback properties of Al-Zn-Mg Al alloy in
creep forming process. Creep forming experiments have been performed at temperatures of 120 °C and 180 °C for 6–
72 h. Results indicated that yield stress and hardness of creep age formed specimens increased with increasing forming
time and temperature, simultaneously induced deflection by stress-relaxation increased. Incorporating spring back
and mechanical properties, it can be found that the appropriate forming cycle was 180 °C/24 h among all forming
conditions. CAF Time increase to a certain extent increased mechanical properties. This can be attributed to presence
of stress in CAF that causes the precipitates be finer because of creation more nucleation sites. Therefor the growth of
precipitates, takes place at long time and postpones the decreasing of the yield stress.
