Embedded lead inclusions in aluminium, aluminium-silicon eutectic alloys and silicon

Small inclusions of Pb have been embedded in pure Al, AlSi composites and pure Si by rapid quenching. Inclusions in aluminium are topotactic truncated octahedra undergoing large overheating and undercooling during in situ TEM thermal treatment. In the composite AlSi there is a definite tendancy for the inclusions to appear only in the aluminium phase. In pure silicon they are topotactic truncated octahedra with a smaller aspect ratio than in Al. They appear also on single and multiple twins with compound morphology. No overheating has been detected whereas undercooling is size dependent and can reach 80 degrees C.