Study on the grain refinement of A356 alloy by Al–3 wt-% VN master alloy

ABSTRACT

A novel Al–3 wt-% VN master alloy, mainly consisting of α-Al and VN phases, was successfully prepared by stir casting. The grain refinement performance of the master alloy on A356 alloy was then investigated. The results showed that the α-Al grain size of A356 alloy refined by Al–3 wt-% VN master alloy was 350 ± 95 µm while that of A356 alloy treated by traditional Al–5Ti–B master alloy was 570 ± 105 µm. Moreover, for A356 alloy with Al–3 wt-% VN addition, the good grain refining efficiency did not fade significantly within 30 min. The effectiveness of grain refinement might be attributed to VN particles, which acted as the heterogeneous nuclei of α-Al grains. Owing to the refinement strengthening, the yield strength, ultimate tensile strength and elongation of A356 alloy were improved.

KEYWORDS:

• Al–3 wt-% VN master alloy
• A356 alloy
• microstructure
• grain refinement
• nucleation
• tensile properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number U16642541], Jiangsu Provincial Key Research and Development Program [grant number BE2015148] and Jiangsu Province Major Scientific and Technological Achievements Transformation Project [grant number BA2017131], [grant number BA2018097].