The effect of microalloying with silicon and germanium on microstructure and hardness of a commercial aluminum alloy

• Published in: Journal of the Serbian Chemical Society Vol. 68; no. 11; pp. 893 - 901
• Main Authors: Maksimovic, Vesna, Zec, Slavica, Radmilovic, Velimir, Jovanovic, Milan
• Format: Journal Article
• Language: English
• Published: Serbian Chemical Society 2003
• Subjects: al alloy 2219; al–cu–si–ge alloys; heterogeneous precipita- tion; precipitate strengthening; si–ge precipitate
• ISSN: 0352-5139; 1820-7421
• DOI: 10.2298/JSC0311893M

The effect of small additions of Si and Ge on the microstructure and hardness was investigated during aging of a commercial 2219 aluminum alloy. It was found that for the same level of microalloying in alloy 2219SG (containing Si and Ge), a maximum hardness was achieved 3 times faster than in alloy 2219S (without Ge). The accelerated precipitation kinetics is a consequence of the presence of fine Si?Ge particles, serving as heterogeneous precipitation sites for ?" strengthening particles. Ispitivan je uticaj malih dodatka Si i Ge na mikrostrukturu i tvrdocu za vreme starenja komercijalne legure aluminijuma 2219. Mikrolegiranje utice na mikrostrukturu legura i kaljenom stanju zbog razlicitog odnosa Si i Ge. Utvrdjeno je da se pri istom nivou mikrolegiranja maksimum tvrdoce u leguri 2219SG (sadrzi Si i Ge) postize tri puta brze nego u leguri 2219S (bez Ge). Ubrzana kinetika talozenja, posledica je prisustva Si?Ge taloga koji sluze kao mesta za heterogeno talozenje ?" faze koja ojacava leguru.