An additively manufactured near-eutectic Al–Ce–Ni–Ti–Zr alloy: microstructure, mechanical properties and heat resistance
Chaoqun Wu, Yinghao Hu, Jianbao Gao, Jinliang Zhang, Jianyu Li, Bo Song, Shiwei Xu, Yusheng Shi
Abstract
Nowadays, heat resistance of additively manufactured aluminum alloys is highly in demand to meet the high-temperature strength requirements for lightweight components. However, existing commercially-available alloys exhibit severe strength degradation at elevated temperatures due to coarsening of strengthening phases. In this study, an additively manufactured near-eutectic Al–Ce–Ni–Ti–Zr alloy with superior heat resistance was developed based on the thermodynamic calculations. The new alloy possesses good printability thanks to the combination of the near-eutectic Al–Ce–Ni composition and inoculation treatment provided by Ti and Zr micro-additions. The eutectic solidification microstructure comprises a high volume of coarsening-resistant Al11Ce3 and Al3Ni phases and presents a typical hierarchical microstructure where refined equiaxed grains decorates melt boundaries. Such microstructure characteristics determine excellent heat resistance and good mechanical properties at ambient and elevated temperatures with 400°C. The alloy possesses a yield strength of 427 MPa and an elongation of 4.7% at ambient temperature. Even at 400°C, the alloy still retains a superb tensile yield strength of 104 MPa and an elongation of 17.86%. This work provides an effective pathway for heat-resistant aluminum alloy design via additive manufacturing and other rapid solidification processes.