Rapid homogeneous precipitation of nano-sized Si in Al-1%Si alloy by electric pulses

Rapid and homogeneous precipitation of nano-sized Si particles with high density was achieved in Al-1%Si alloy by electric pulses treatment (EPT) in a liquid nitrogen bath (similar to 77 K). In contrast, when processed by EPT in air or by high-temperature (527-720 K) salt bath treatment, the precipitate density decreases dramatically. The homogeneous precipitation of Si could be facilitated by both the low-temperature environment and the non-thermal effects of EPT. The low-temperature environment provides a high driving force for nucleation, and retains the quenched-in vacancies serving as potential nucleation sites. The non-thermal effects of EPT can significantly promote local migration of solutes and vacancies at such low temperatures.

Automated summary

Homogeneous precipitation of nano-sized Si particles with high density was achieved in Al-1%Si alloy by electric pulses treatment in a liquid nitrogen bath. This was attributed to both the low-temperature environment and the non-thermal effects of EPT.