The effect of Zn+and Cd+primary ions with energies between 3 and 10 keV on the emission of secondary Cu+, Cu+2, and Mo+ions from polycrystalline copper and molybdenum target surfaces has been investigated. It was found that secondary ion intensity increases almost linearly with bombarding ion energy, attains a broad maximum, and then decreases steadily. It has also been observed that the location of the maximum depends strongly on the ion‐target combination. The positions of maxima were found to be around 7.5, 6.5, and 5.0 keV for Zn+‐Cu, Cd+‐Cu, and Cd+‐Mo combinations, respectively. Our finding could be experimental evidence of the fact that the nontextured surfaces may become textured under ion bombardment.