Microstructure Evolution and Mechanical Properties of an Al-Si-Cu-Mg-Ni Aluminium Alloy after Thermal Exposure

Abstract:

The microstructures and mechanical properties of an Al-Si-Cu-Mg-Ni aluminium alloy have been investigated after thermal exposure at 350 °C for time intervals up to 1000 h. Experimental results showed that, with increasing the thermal exposure time, room temperature ultimate tensile strength, elevated temperature ultimate tensile strength, and Brinell hardness firstly decreased remarkably (up to 100 h) and then decreased slightly to a certain constant value (100-1000 h). Before thermal exposure, room temperature ultimate tensile strength, elevated temperature ultimate tensile strength, elevated temperature elongation percentage, and Brinell hardness of the alloys are 203.5 MPa, 48.7 MPa, 9.2%, and 82.3, respectively. With increasing the thermal exposure time, eutectic silicon grows up steadily, and the amount of Q phase with a flower shape increases. Transmission electron microscopy analysis showed that the formation of stable θ precipitates was found in the microstructure.

• Periodical: Materials Science Forum (Volume 765)
• Pages: 486-490
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.765.486
• Online since: July 2013
• Authors: Feng Xia, Jian Ping Li, Yong Chun Guo, Zhong Yang
• Keywords: Al-Si-Cu-Mg-Ni Alloys, Mechanical Property, Microstructure, Thermal Exposure

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