Microstructural Evolution of Undercooled Ni-40wt%Pb Hypermonotectic Alloy

Abstract

Microstructural evolution of bulk undercooled Ni-40wt%Pb hypermonotectic alloy was systematically investigated by using molten glass purification and superheating cycling. Within the achieved undercooling range, the microstructures were classified into three categories. When the undercooling was less than 50K, the microstructure consisted of coarse dendritic grain and interdendritic Pb lumps. Increasing undercooling to the range 100 to 198K, macrosegregation was serious. When the undercooling was up to 292K, refined granular grain with homogeneously distributed fine Pb particles on it formed. The granulation mechanism of granular grains was owing to dendritic disintegration and subsequent recrystallization.

New high-pressure and high-temperature metal/silicate partitioning of U and Pb: Implications for the cores of the Earth and Mars

“…4) are consistent with textures developing during quench (e.g. Zheng et al, 2003Zheng et al, , 2005Sanloup and Fei, 2004;Siebert et al, 2004). Finally, the comparison of the metallic textures between the ''Fe-Si'' samples and the ''Fe-S'' samples ( Fig.…”