铝合金型材缺陷远场涡流检测仿真与试验研究

基于铝合金型材远场涡流检测技术，建立了铝合金型材内部埋深缺陷检测有限元模型，设计研发了横跨式远场涡流传感器，同时搭建了远场涡流试验检测系统，测试试验了不同频率、埋深检测信号特征以及横跨式远场涡流传感器中激励线圈与检测线圈位置对检测信号的影响。试验结果显示，300 Hz频率时检测信号的强度最大；激励线圈中心与检测线圈中心相距20 mm时检测效果最佳；传感器在无提离时对缺陷信息有着更好的测量能力，同时在提离高度1～3 mm时也能测量到缺陷信号；优化后的探头可检测埋深为2 mm、尺寸为63 mm×0.2 mm×8 mm的隐藏缺陷。结果表明，设计的横跨式远场涡流传感器能够实现对裂纹缺陷的定位检测。

Simulation and Experimental Study of Far Field Eddy Current Sensor for Defect Detection of Aluminum Alloy Profiles

Based on far field eddy current testing technology for aluminum alloy profiles, the finite element model for detection of buried defects in aluminum alloy profiles is established, and the straddle type far field eddy current sensor is designed and developed. Meanwhile, the far field eddy current testing system is built, and the influence of different frequencies, buried depth detection signal characteristics and the position of excitation coil and detection coil in straddle type far field eddy current sensor on the detection signal are tested. The test results show that intensity of the detection signal is the highest at 300 Hz and the detection effect is best when the distance between the excitation coil center and detection coil center is 20 mm. The sensor has better measurement capability for defect information when there is no lift off, and can also measure defect signal when the lift off height is 1~3 mm. The optimized probe can detect a buried depth of 2 mm and a size of 63 mm × 0.2 mm × 8 mm hidden defects. The results show that the designed straddle type far field eddy current sensor can realize the location detection of crack defects.