Showing 3 results for Age Hardening
M. S. Kaiser, A. S. W. Kurny,
Volume 8, Issue 4 (12-2011)
Abstract
Microstructure and properties of the Al-6Si-0.3Mg alloys containing scandium (0.2 to 0.6wt %) were investigated. The microstructure was observed by optical microscopy, the hardness was determined by Vickers tester and phase transformation was investigated by differential scanning calorimetry (DSC) technique. The results showed that scandium can refine dendrites, enhance hardness in the aged alloys and suppress softening effect during prolonged ageing treatment.
E. Mousavi, M. R. Aboutalebi, S. H. Seyedein, S. M. Abbasi,
Volume 11, Issue 3 (9-2014)
Abstract
The effect of aging time and temperature on the microstructure and mechanical properties of Ti-13V-11Cr-3Al and Ti-13V-11Cr-3Al-0.2C was studied. The carbon addition increases the rate of age hardening as well as the
peak hardness of aged samples. The presence of titanium carbides in Ti-13V-11Cr-3Al-0.2C limits grain growth during
the process. The observations in this work are discussed in terms of the effect of the microstructural changes in
quenched and aged samples associated with the presence of carbide precipitates
M. Ershadi Khameneh, H. Shahverdi, M. M. Hadavi,
Volume 12, Issue 4 (12-2015)
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
