Bi-Pb alloy at the eutectic composition was unidirectionally solidified upwards with five different growth rates (V 7.05-113.09 mu m/s) at constant temperature gradient (G = 2.18 K/mm) in a Bridgman type directional growth furnace in order to investigate dependency of eutectic spacing (lambda), minimum undercooling (Delta T) and microhardness (HV) on the growth rates (V). The values of lambda and HV were measured from the quenched samples and the minimum undercooling (Delta T) were determined from the Jackson-Hunt eutectic theory. The dependency of eutectic spacings, microhardness and undercooling on growth rate was investigated. According to these results it has been found that the value of lambda decreases with increasing the value of V and that the values of HV and Delta T increase for a constant G. The values of lambda V-2, lambda Delta T and Delta TV-0.5 were determined by using the values of lambda, Delta T and V. The results obtained in the present work have been compared with those predicted by the Jackson-Hunt eutectic theory and with similar experimental results. (c) 2012 Elsevier B.V. All rights reserved.