Autori: Maria-Cristiana Enescu, Ileana-Nicoleta Popescu, Raluca Zamfir, Alina Molagic, Vasile Bratu
Editorial: WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC, AG LOANNOU THEOLOGOU 17-23, 15773 ZOGRAPHOU, ATHENS, GREECE, ADVANCED MANUFACTURING ENGINEERING, QUALITY AND PRODUCTION SYSTEMS Book Series: Electrical and Computer Engineering Series, 1, p.212-216, 2010.
The influence of heat treatment parameters on mechanical characteristic of hardness and corrosion of aluminum alloys were studied. The 7xxx series aluminium alloy in rolled state was heat treated in the following conditions: solution treatment at 475+/-5oC for 60 minutes, quenched in water 40-60oC and artificial aging at 120, 150, 180, 210oC at different time of aging (60, respectively 300, 540, 720 minutes). The research consisted in intercrystalline corrosion and hardness tests in correlation with microstructure analysis of heat treated Al-Zn-Mg-Cu samples alloy, in order to obtain the best corrosion resistance and high mechanical characteristics. We observed that the hardness modifications and the variation of electrode potential are in correlation with structural modification which have place during aging. Thus, when temperature and the duration of aging increases, we achieves the maximum hardness (fine precipitates occurred), and when the hardness decrease, this phenomenon is resulted of appearance of coarse precipitates. The polarization curves show two zones: one which characterize an active process, in which corrosion current intensity increases over a small range of potential and second one, the passivation zone, which are characterized of a small change in current intensity within a high potential
Cuvinte cheie: 7xxx aluminum alloys; Artificial ageing; Microstructure analysis; General corrosion