对压铸镁合金冷却叶轮替代铝合金冷却叶轮进行了振动性能的分析。通过模态试验 ,得到了叶轮的固有频率和固有振型等主要模态参数 ,同时根据振幅衰减信号测得了镁合金AZ91D和铝合金A3 80的材料减振系数 (SDC)。试验结果表明 ,镁合金对叶轮的模态参数改变不大 ,减振系数比铝合金的增加了 10倍以上 ,极大地改善了叶片的振动性能 ,减小了叶轮的工作噪声 The vibration performance of die-cast magnesium alloy cooling impeller instead of aluminum alloy cooling impeller was analyzed. Through the modal test, the main modal parameters such as the natural frequency and the natural mode of the impeller are obtained, and the material damping coefficient (SDC) of the magnesium alloy AZ91D and the aluminum alloy A380 is measured according to the amplitude attenuation signal. The experimental results show that the modal parameters of the magnesium alloy have little change to the impeller, and the damping coefficient is more than 10 times higher than that of the aluminum alloy, which greatly improves the vibration performance of the blade and reduces the working noise of the impeller