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.