随着增材制造在各个领域更为广泛和深入应用，越来越多的增材制造产品需要快速、无损的质量检测.孔隙率作为决定增材制造产品力学性能的重要指标，其检测更是重中之重. 通过调整激光功率、扫描速度改变体积能量密度，得到不同孔隙率的AlSi10Mg试样.分别采用超声横波、纵波对各试样进行检测，得到对应声速与衰减系数.结果表明，横、纵波声速均与孔隙率成反比关系，衰减系数与孔隙率均成正比关系.使用声速对孔隙率进行表征时，纵波声速绝对值变化更大，所以精度更佳.又由于纵波声速相较横波声速所对应的剪切模量变化更大，所以线性程度比横波提高22%；而使用衰减系数对孔隙率表征时，由于同频率横波波长更短，对极化方向更敏感，所以横波精度优于纵波，线性程度相较纵波提高13%.
With more extensive and in-depth application of additive manufacturing in various fields, non-destructive inspection are in growing needs in additive products for its fast and high quality inspection. Porosity is an important factor determining the mechanical properties of the additive products, so it is very important to characterize it during the inspection process. In this paper, the laser power and scanning speed are adjusted to change the volume energy density, and the AlSi10Mg specimens with different porosities are obtained. The ultrasonic transverse and longitudinal waves were used to test the specimens, and the corresponding sound velocity and attenuation coefficient were obtained. The results show that the transverse and longitudinal sound speeds are inversely proportional to the porosity size, and the attenuation coefficients are directly proportional to the porosity size. When using sound velocity to characterize the porosity, the absolute value of longitudinal sound velocity is more variable, so the accuracy is better. Because the shear modulus of longitudinal sound velocity changes more than that of transverse sound velocity, the linearity is 22% higher than that of transverse sound velocity. When the attenuation coefficient is used to characterize the porosity, the accuracy of transverse wave is better than that of longitudinal wave because transverse wave of the same frequency is shorter in wavelength, and is more sensitive to the direction of polarization, so the linearity is 13% higher than that of the longitudinal wave.
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