Growth of Ω Plates and Its Effect on Mechanical Properties in Al-Cu-Mg-Ag Alloy with High Content of Silver

• Published in: Journal of materials engineering and performance Vol. 22; no. 6; pp. 1708 - 1715
• Main Authors: Gu, Yanxia, Liu, Zhiyi, Yu, Dier, Liu, Bingbin, Lin, Mao, Zeng, Sumin
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.06.2013; Springer
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Cross-disciplinary physics: materials science; rheology; Elasticity. Plasticity; Engineering Design; Exact sciences and technology; Materials Science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; Quality Control; Reliability; Safety and Risk; Tribology; Mechanical properties; Growth; Al-Cu-Mg-Ag alloy; Ω plates; Aluminium base alloys; Volume fraction; Ageing; Tensile property; Hardness; Alloying element; Habit plane; Tensile strength; Precipitation; Microstructure
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-013-0472-8

In this study, the effects of thermal exposure at 200 °C on the mechanical properties and the growth of Ω plates in an Al-Cu-Mg-Ag alloy with high content of silver were investigated. It was shown that the tensile strength of the exposed alloy decreased with the increase of the mean lengths of Ω precipitates and the decrease in the volume fraction of the Ω phase. The decrease in tensile strength of the 165 °C/14-h-aged samples was less significant than that of 165 °C/2-h-aged samples because the lengthening rate of Ω plates was lower and the number density of Ω precipitates was higher in the 165 °C/14 h-aged samples. The thickening rate of Ω plates was very low during exposure at 200 °C because of high content of silver, and the growth behavior was caused mainly by the lengthening of Ω plates within the habit plane. High content of silver inhibited the thickening of Ω plates and promoted the lengthening of Ω precipitates during exposure.