Experimental Ce and ultrasonic treatment improves Al–Si–Cu–Ni melt purity and casting properties

An experimental study reported in the Journal of Materials Science found that adding 0.1 wt% cerium and applying 2,000 W of ultrasound for 15 seconds produced the best measured melt-purification results for Al–Si–Cu–Ni alloy. Under this condition, the casting density index decreased from 0.262 to 0.026, while hydrogen content fell from 180.28 ppm to 48.64 ppm and oxygen content declined from 47.32 ppm to 18.51 ppm.

The researchers examined cerium additions of 0, 0.1%, 0.3% and 0.5% in combination with ultrasonic powers of 0, 1,000, 2,000 and 3,000 W and treatment durations of 0, 10, 15 and 20 seconds. Gas content in the castings was evaluated through density index, porosity analysis and confocal laser scanning microscopy. Hydrogen and oxygen contents were measured with a nitrogen–oxygen–hydrogen analyzer. The findings summarize comparisons across the tested parameter combinations; they do not establish that the same treatment will be equally effective for other alloy compositions or operating conditions.

The abstract attributes the observed relationship between viscosity and hydrogen content to cerium’s reported ability to increase bubble-rising velocity and lower the ultrasonic cavitation-threshold pressure. It also reports that precipitated CeO₂ served as heterogeneous nucleation sites. The density index of the castings varied consistently with melt viscosity, and lower melt viscosity was associated with lower hydrogen content. These proposed mechanisms are interpretations presented in the abstract rather than independently verified findings available in the supplied material.

Castings produced with the optimized combination also showed higher mechanical properties than the comparison conditions described by the authors. At ambient temperature, ultimate tensile strength reached 279.9 ± 5.0 MPa, yield strength reached 115.4 ± 3.0 MPa and elongation reached 1.1 ± 0.2%. At elevated temperature, the respective values were 90.6 ± 3.0 MPa, 81.0 ± 2.2 MPa and 16.5 ± 0.8%. The abstract associates the improved properties with greater melt cleanliness and an optimized microstructure. Because only the abstract and publisher preview were supplied, the full methods, statistical analyses, comparison values, replicate details and specification of the elevated-temperature test are not available for assessment.

Subject of Research: Cerium-assisted ultrasonic purification of Al–Si–Cu–Ni alloy melt

Article Title: Ultrasonic field-enhanced rare-earth Ce purification of Al–Si–Cu–Ni melt

Article References: Hu, D., Li, J., Bian, Y., Wan, Z., Fang, J., Zhao, D., & Guan, R. (2026). Ultrasonic field-enhanced rare-earth Ce purification of Al–Si–Cu–Ni melt. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13884-5

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13884-5

Keywords: Al–Si–Cu–Ni alloy, cerium purification, ultrasonic treatment, melt metallurgy, hydrogen removal, oxygen removal, cast microstructure, mechanical properties, Ultrasonic, field-enhanced, rare-earth, purification