Abstract: The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on the mechanical properties of Pd was studied. All above RE additions increased not only the strength properties at ambient temperature but also the tensile strength, creep rupture time and activation en- ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con- centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. When the strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light RE elements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma- lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yb and Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasing recrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den- sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and so on, were observed. They were strengthening sensitive factors. The influence of the factors on strength properties and elongation of Pd was discussed.

Key words: RE, mechanical property, Pd