Article ID Journal Published Year Pages File Type
8011743 Transactions of Nonferrous Metals Society of China 2017 9 Pages PDF
Abstract
Transmission electron microscopy (TEM), scanning electron microscopy (SEM), hardness tests and tensile tests were performed to investigate the effect of aging on microstructure and mechanical properties of forged Al-4.4Cu-0.7Mg-0.6Si alloy. The results show that the alloy exhibits splendid mechanical properties with an ultimate tensile strength of 504 MPa and an elongation of 10.1% after aging at 170 °C for 16 h. With tensile testing temperature increasing to 150 °C, the strength of the alloy declines slightly to 483 MPa. Then, the strength drops quickly when temperature reaches over 200 °C. The high strength of the alloy in peak-aged condition is caused by a considerable amount of θ′ and AlMgSiCu (Q) precipitates. The relatively stable mechanical properties tested below 150 °C are mainly ascribed to the stability of θ′ precipitates. The growth of θ′ and Q precipitates and the generation of θ phase lead to a rapid drop of the strength when temperature is over 150 °C.
Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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