Effect of eutectic particles on the grain size control and the superplasticity of aluminium alloys

Aluminium alloys containing eutectic particles of the Al–Ni, Al–Mg–Si, Al–Ni–Ce and Al–Cu–Ce systems are investigated. The particles which control grain growth and stimulate grain nucleation are studied. The Zener–Smith law about dependence between grain size and particle parameters is confirmed and experimental coefficients are found. Experimental coefficients of the Zener–Smith equation obtained in this study depend on the particle size and differ from theoretical coefficients proposed by Zener and Smith. Some alloys with grain size about 3 μm demonstrate very good superplasticity indicators, namely: the strain rate sensitivity index m = 0.5–0.6 and the elongation over 400% at constant strain rate 5 × 10−3 s−1.