在A356铝合金熔体中添加Al₉₀Y₁₀非晶合金细化剂进行细化处理，研究了细化剂质量分数（0，0.2%，0.4%，0.6%，0.8%，1%）对铝合金显微组织及力学性能的影响，分析了细化机制。结果表明：随Al₉₀Y₁₀细化剂含量增加，A356铝合金的二次枝晶间距先减小后增大，抗拉强度、屈服强度、断后伸长率和硬度先升高后降低，拉伸断裂形式由准解理断裂转变为准解理与微孔聚集型混合断裂；当细化剂质量分数为0.6%时，A356铝合金的二次枝晶间距比未细化的下降了39.68%，合金力学性能最好；适量添加Al₉₀Y₁₀细化剂后形成的钇聚集相能够减少脆性相析出，阻碍α-Al相和共晶硅相进行溶质交换，从而细化晶粒，改善力学性能。

Al₉₀Y₁₀ amorphous alloy was added to A356 aluminum alloy melt as refiner to refine the alloy. The effect of refiner mass fraction (0, 0.2%, 0.4%, 0.6%, 0.8%, 1%) on the microstructure and mechanical properties of the aluminum alloy was studied. The results show that with the increase of Al₉₀Y₁₀ refiner content, the secondary dendrite spacing of the A356 aluminum alloy decreased first and then increased, the tensile strength, yield strength, elongation after fracture and hardness increased first and then decreased, and the tensile fracture form changed from quasi-cleavage fracture to quasi-cleavage and micropore aggregation mixed fracture. When the mass fraction of the refiner was 0.6%, the secondary dendrite spacing of the A356 aluminum alloy was 39.68% lower than that of the unrefined alloy, and the alloy showed the best mechanical properties. The yttrium aggregate phase formed after adding Al₉₀Y₁₀ refiner in moderation could reduce the precipitation of brittle phase, hinder the solute exchange between α-Al phase and eutectic silicon phase, thereby refining grains and improving mechanical properties.