Fabrication, microstructure and refining mechanism of in situ CeB6/Al inoculant in aluminum

• CeB6/Al ribbon as aluminum alloy inoculant was prepared by melt-spinning.
• Grains of Al were significantly decreased with 0.4% CeB6/Al ribbon.
• Mechanical properties of Al have been improved by addition of CeB6/Al ribbon.
• CeB6/Al interface is smooth and clean.

The CeB6/Al inoculant with variable sizes of CeB6 particles were prepared by arc-melting and controlled by melt-spinning and then verified the refining efficacy in pure aluminum. It was found that the grain refining efficacy can be significantly improved by controlling the CeB6 particle size. The pure aluminum can be refined from a grain size grade of 870 ± 25 μm to 150 ± 35 μm by addition of CeB6/Al ribbon with a very small ratio of 0.4% in weight. Thereafter, the mechanical properties of the pure aluminum, including the tensile strength, yield strength and microhardness, were obviously improved by the addition of the CeB6/Al ribbon. The excellent grain refining can be attributed to the nano-sized refiner particles and the well-banded particle/matrix interface which are benefit for the nucleation of aluminum during solidification. It is suggested that the CeB6/Al inoculant ribbon is a promising inoculants for aluminum alloy.