Ultrasonic Inspection of Thin Coatings Using Surface Waves

9812820哈里斯薄膜或涂层被用作热屏障，以增加发动机部件的制造硬度。在零件投入使用前，开发无损检测此类涂层以评估其质量的方法非常重要。建立了描述涂层变薄、剥落或破裂引起的超声波的时延和传输损耗或衰减的解析表达式。表面波特别有用，因为它们比从涂层表面反射的波采样更大的涂层体积，并提供更强的接收信号。这项工作是与卡特彼勒公司合作完成的。***

9812820 Harris Thin films or coatings are used as thermal barriers to increase hardness in the manufacture of engine parts. It is important to develop ways to nondestructively inspect such coatings to assess their quality before a part is placed in service. Analytical expressions that describe the time delay, and transmission loss or attenuation of ultrasonic waves caused by thinning, flaking, or cracking of the coatings are developed. Surface waves are especially useful as they sample a larger volume of the coating than do waves reflected from coated surface and provide stronger received signal. The work is done in collaboration with Caterpillar Corporation. ***