为研究Al-Si合金弹性模量与合金中Si相含量及其形态的相关性， 通过熔体法制备了亚共晶Al-3Si、 Al-5Si、Al-7Si、Al-9Si 合金、近共晶 Al-12.5Si 合金及过共晶 Al-18Si 合金，并对 Al-9Si、Al-12.5Si 和 Al-18Si 合金分别进 行了P变质和Sr变质处理。 通过声速法测量了合金的弹性模量，利用ImageJ软件获得了合金微观组织中Si相的面积 分数，并揭示了其与Si相体积分数的相关性，经数据拟合分别得到合金弹性模量与合金中Si含量及微观组织中Si相 面积分数的函数关系。 结果表明，随着Si含量的增加，合金的弹性模量不断提高。 经P变质和Sr变质处理后，Al-9Si、 Al-12.5Si 和 Al-18Si 合金的弹性模量均降低，分析认为，Si相形态变化导致合金中Si相体积分数的降低，进而引起合金 弹性模量的变化。

To study the relationships between the elastic modulus of Al-Si alloys and the content and morphology of the Si phase, hypereutectic Al-3Si, Al-5Si, Al-7Si, Al-9Si, near-eutectic Al-12.5Si and hypoeutectic Al-18Si alloys were prepared via the melting method, and the Al-9Si, Al-12.5Si and Al-18Si alloys were modified with P and Sr, respectively. The elastic modulus of the alloys was detected via the sound velocity method. The area fraction of the Si phase in the microstructures was measured via ImageJ software, and its relationship with the volume fraction of the Si phase was revealed. The functional relationships between the elastic modulus of the Al-Si alloys and the Si content and the area fraction of the Si phase in the microstructures were obtained via data fitting. The results show that with increasing Si content, the elastic modulus of the alloys increases continually. After being modified by P and Sr, the modulus of the selected Al-9Si, Al-12.5Si and Al-18Si alloys decreases. The morphological change in the Si phase leads to a decrease in the volume fraction of the Si phase, which results in a change in the elastic modulus.