不同激活孔径和聚焦深度对相控阵超声横波检测灵敏度的影响

Influence of different activation apertures and focus depths on the sensitivity of phased array ultrasonic shear wave detection

为探究相控阵超声检测过程中,激发晶片数、激活孔径和聚焦深度对检测灵敏度的影响,通过试验测定了3组激活孔径和不同聚焦深度下,一系列不同深度横通孔在55°横波下的检测灵敏度。研究了固定孔径条件下不同聚焦深度对灵敏度的影响以及固定孔深条件下不同激活孔径和聚焦深度与灵敏度的关系。试验结果表明,聚焦会提高焦点处的灵敏度,且大多数情况下有效晶片面积越大灵敏度越高,但越过焦点之后,相比未聚焦状态,灵敏度会下降得更快。因此在实际检测中,对不同的检测区域,应根据不同探头的声场能量分布选择合适的检测工艺,以得到更优化的检测效果。

In order to explore the influence of the number of excited wafers, the activation aperture and the depth of focus on the detection sensitivity in the phased array ultrasonic testing process, through experiments, the detection sensitivity for a series of different depths of transverse through holes by 55° shear waves was determind under three sets of activation apertures and different focus depths. The effects of different focus depths on sensitivity under fixed aperture conditions and the relationship between different activation apertures and focus depths and sensitivity under fixed aperture depths are studied. Experimental results show that focusing will increase the sensitivity at the focal point, and in most cases the larger the effective wafer area, the higher the sensitivity, but after passing the focal point, the sensitivity will decrease faster than in the unfocused state. Therefore, in actual detection, for different detection areas, a suitable detection process should be selected according to the sound field energy distribution of different probes to obtain a more optimized detection effect.