Development of new Al-Cu-Si alloys for high temperature performance

¹Department of Materials and Manufacturing, School of Engineering, Jönköping University,  Gjuterigatan 5, P. O. Box 1026, SE-551 11, Jönköping, Sweden

²Korea Institute of Industrial Technology, Dongnam Technology Application Division,  Offshore Plant Resources R&D Center, #214, 1274, Jisa-dong, Gangseo-gu,  Busan 618-230, Korea

Adv. Mater. Lett., 2017, 8 (6), pp 695-701

DOI: 10.5185/amlett.2017.1471

Publication Date (Web): Apr 30, 2017

Copyright © IAAM-VBRI Press

E-mail: Samuel.Awe@ju.se

Abstract

In a quest for developing new lightweight metal alloys that can perform excellently at elevated-temperatures (from 300°C to 400 °C), a ternary eutectic Al-Cu-Si alloy was exploited to gain a deeper understanding of the alloy system and its suitability for high temperature applications. The studied alloys, with chemical composition of Al-27%Cu-5%Si (by weight percent) with Ni addition in the range of 0 to 1.5%wt, were cast in a rapid solidification casting technique. The solidification characteristics of the alloy was studied using the Thermo-Calc software. Microstructures were characterized in a scanning electron microscope coupled with energy dispersive spectrometry (SEM-EDS). Finally, the elevated-temperature tensile properties of the alloys were investigated. Comparing the microstructures and mechanical properties of the Al-Cu-Si(-Ni) alloys with conventional A319 Al- alloy, the refined microstructure with dispersed Ni intermetallic particles formed in the as-cast Al-Cu-Si(-Ni) alloys delivers improved elevated temperature properties. In particular, the yield strength and ultimate tensile strength of the new alloy with 1.5% Ni at 400˚C were observed to be 220% and 309% higher, respectively, than for conventional A319 reference alloy.

Keywords

Eutectic composite structure, casting, solidification, elevated-temperature performance, thermo-calc, tensile properties.