中文摘要：

研究了机械振动对消失模铸造AlSi9Mg合金组织与性能的影响,并分析了其作用机理。结果表明,Z方向机械振动的AlSi9Mg合金的平均晶粒尺寸最小,布氏硬度、抗拉强度和伸长率最大,其次为XY方向,而X、XZ和XYZ方向振动的AlSi9Mg合金的平均晶粒尺寸稍大,布氏硬度、抗拉强度和伸长率相对较小。随着机械振幅或振动频率的增加,AlSi9Mg合金的平均晶粒尺寸呈现先减小而后增加的趋势,而布氏硬度、抗拉强度和伸长率都呈现为先增加而后降低的趋势。消失模铸造AlSi9Mg合金适宜的机械振动工艺：机械振动方向为Z向,机械振幅为0.10mm,机械振动频率为36 Hz,在此工艺下可以获得较好的强度与塑性。

英文摘要：

Influences of mechanical vibration,amplitude and frequency on microstructure and mechanical properties of the AlSi9 Mg alloy were investigated,and the mechanism of its action was described.The results show that the average grain size of AlSi9 Mg alloy in Zdirection is the smallest,and hardness,tensile strength and elongation of the alloy reach maximum values,respectively,followed by XY,while average grain size of the AlSi9 Mg alloy in X,XZand XYZdirection is slightly increased,and Brinell hardness,tensile strength and elongation rate are relatively decreased.With the increase of the mechanical vibration amplitude and vibration frequency,average grain size of the AlSi9 Mg alloy is decreased firstly and then increased,while hardness,tensile strength and elongation of the alloy are increased firstly and then decreased.The suitable mechanical vibration parameters for AlSi9 Mg alloy in lost foam casting are presented as follows：mechanical vibration direction in Zdirection,mechanical amplitude of0.10 mm,mechanical vibration frequency of 36 Hz,and the desirable strength and plasticity can be obtained under the optimized parameters.