Effect of heat treatment on microstructures and mechanical properties of Al/Fe bimetal

ABSTRACT

The Al/Fe bimetallic castings were prepared by the compound casting combined with hot-dip galvanising and aluminising, and the effect of the heat treatment on microstructures and mechanical properties of the Al/Fe bimetallic castings was systematically studied in the present work. The thickness of the reaction layer of the Al/Fe bimetallic castings continuously increased with increasing solution temperature or prolonging solution time. However, the excessive solution temperature and solution time promoted cracks of the reaction layer. Regardless of as-cast or heat treatment, there were respectively the Fe₂Al_5, Al₉Fe₄Si_3, FeAl_3, Al₈Fe₂Si and Al_4.5FeSi phases in the reaction layers. The nano-hardnesses of the reaction layer after heat treatment exhibited an increase compared to that of the as-cast condition.

KEYWORDS:

• Heat treatment
• Al/Fe bimetallic castings
• interface
• intermetallic compounds
• microstructure
• mechanical properties

Acknowledgements

The authors would also like to thank the support of the Research Project of State Key Laboratory of Materials Processing and Die & Mould Technology and the Analytical and Testing Center, HUST.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Grant No. 51204124 and No. 51775204), and the Natural Science Foundation of Hubei Province, China (Grant No. 2017CFB488).