以TC4 钛合金激光立体成形件为研究对象，探讨其内部、表面及近表面孔洞类缺陷与超声波的相互作用关系。研究结果表明，在相同检测条件下，对于TC4钛合金激光立体成形件中同深度不同孔径的长横孔缺陷，超声反射波幅值随长横孔直径的增加而增加；对于成形件中同孔径不同深度的长横孔缺陷，超声反射波幅值随长横孔所在深度增加而减小；利用5PФ8 纵波直探头，能发现激光立体成形TC4 钛合金中0.6 mm 大小的孔洞类缺陷；超声表面波沿深度方向发现TC4钛合金激光立体成形件中槽型和孔型缺陷的能力均小于4 mm，且孔型缺陷比槽型缺陷更难发现。

The interaction between the inner, surface and near- surface defects of laser solid forming TC4 alloy and ultrasonic are studied. The results show that under the same testing conditions, reflection amplitude value increases with the increasing of long lateral hole diameter for the long lateral hole defects with the same depth and different diameters; and the reflection amplitude value decreases with the increasing of the depth of long lateral hole for the long lateral hole defects with the same diameter and different depths; holes within 0.6 mm diameter can be found in laser solid forming TC4 alloy using 5PФ8 straight longitudinal wave probe. The ability of SAW to found defects less than 4mm from the surface in the depth direction is less than 4 mm and the hole defect is harder to find than the groove.