基于超声红外热成像技术的涡轮叶片裂纹检测

Turbine blade crack detection based on ultrasonic infrared thermography

使用等离子喷涂工艺对涡轮叶片喷涂镍铬铝钇涂覆层,采用超声红外热成像技术对喷涂前和喷涂后的涡轮叶片进行检测,可以检测到2处裂纹缺陷;采用渗透检测技术只能检测到喷涂前涡轮叶片的1处裂纹缺陷,无法检测出喷涂后涡轮叶片的裂纹缺陷;最后对喷涂后的涡轮叶片进行剖析和金相显微镜检测,发现2处裂纹缺陷,验证了超声红外热成像技术对含涂覆层涡轮叶片裂纹检测的有效性。对比试验表明,超声红外热成像技术可检测喷涂前和喷涂后涡轮叶片的裂纹缺陷。

The plasma spraying process was adopted to spray the turbine blade with NiCrAlY coating.ultrasonic infrared thermography technique was used to detect turbine blade before and after spraying and achieve two crack defect detection.The penetration detection technology can only detect one crack defect in the turbine blade before spraying and however cannot detect crack defects in the turbine blade after spraying.Finally,the turbine blade after spraying was dissected and detected by metallographic microscopy and two crack defects were found.It verified the effectiveness of ultrasonic infrared thermography for crack detection of turbine blade with coating layer.The comparison results show that ultrasonic infrared thermography can detect the crack defects in turbine blades before and after spraying.