金属增材制造产品的材料特性相对于传统制造工艺的有所不同,故原有超声无损检测方法不再适用。为探索金属增材制品的超声无损检测特性,提高超声无损检测精度,采用激光熔化沉积工艺并以TA15钛合金作为材料,制作具有相同外形尺寸、不同激光功率和搭接率的检测样块。使用相控阵超声设备对比分析了不同工艺参数下该材料的接触式超声波纵波灵敏度和声速。结果表明:激光功率对超声检测灵敏度影响较大;成形方向和工艺参数对超声声速有影响,其中成形方向影响较大。因此,对比试块的材料和工艺参数应与待检件相同,检测时需对待检件每个检测方向的声速分别进行标定。

Since the material properties of metal additive components differ from those produced by traditional manufacturing processes, the original ultrasonic nondestructive testing methods are no longer applicable. To study the ultrasonic nondestructive testing characteristics of metal additive components and improve the ultrasonic nondestructive testing accuracy, TA15 alloy specimens are prepared by laser melting deposition with different laser powers and overlap rates. The sensitivity and sound velocity of the longitudinal wave, which are excited by contact ultrasonic testing with a phased array ultrasonic equipment, are compared and analyzed. Results show that ultrasonic sensitivity is considerably affected by laser power. Ultrasonic velocity is affected by the forming direction and process parameters. Forming direction is a more important parameter. The material and process parameters of the reference block should be the same as those of the parts to be tested. In addition, the sound velocity in each detection direction of the parts should be calibrated.