双金属结合面缺陷的凸面相控阵超声检测

采用凸面相控阵探头检测双金属涡轮盘内部,根据小孔径涡轮盘结合面缺陷的结构特征、双金属涡轮盘的结构特点以及扩散焊工艺的连接特点等,首先在理论上分析了相控阵超声的声场特性,然后利用CIVA仿真软件设计了一种8阵元凸面相控阵换能器,通过选择合适的相控阵参数,有效地抑制了声束扩散,并在涡轮盘试块中获得了较好的聚焦效果。检测结果表明,设计的凸面相控阵超声探头能够实现对小孔径远距离的聚焦,聚焦效果良好,能对缺陷进行准确定位,检测精度可达1mm平底孔当量。

Convex phased array ultrasonic testing of bimetallic junction surface defect

The convex phased array probe was adopted for internal testing of bimetallic turbine disk.Focusing on defective structural features of small-bore turbine disk junction surface and in accordance with the structural features of thermometal turbine disk and connection features of diffusion welding process,it firstly conducts theoretical analysis on the sound field performance of ultrasonic phased array,and then uses CIVA simulation software to design a 8-array convex phased array energy converter.Suitable phased array parameters are selected to effectively restrain the beam spread in disk and get good focusing effect in turbine disk test block.Detecting results indicate that the designed ultrasonic convex phased array probe can focus small bore diameter in long distance,with good focusing effect,and can accurately position defects.Its detection accuracy can reach 1 mm flat-bottomed hole equivalent.