端点衍射法测量表面开口缺陷深度试验研究

Experimental Research on Depth Measurement of Surface Breaking Crack by Tip Diffraction Method

介绍了一种金属零部件表面开口裂纹深度的超声波测量方法,利用裂纹端点衍射、端角反射原理,可直接在预先校准好时基线的数字式超声检测仪的屏幕上读出裂纹的深度。在钢材料中制作了不同深度的人工裂纹,并用此方法测量其裂纹深度。结果表明,该方法可以测量出深度不小于3mm的裂纹,而且其他裂纹的测量值与实际值相近。此方法操作方便,裂纹深度直读,可应用于有限空间(如在役飞机机舱内)金属零部件表面开口裂纹的深度测量。

In this paper,a method of metal component,by which the crack depth can be directly read on the screen of a digital ultrasonic instrument by the principle of crack tip ultrasound diffraction and block corner reflection,is introduced to measure the surface breaking crack depth.Artifitial cracks of different depths on the steel material were measured by this meathod.In conclusion,cracks no deeper than 3 mm can be detected and measured quantitively,and the measuring value of other cracks is approximately equal to the actural value.This method can be applied in surface breaking crack depth measurement in metal component inside finite space(ex.the cabin of aircraft in service)due to the easy operation and crack depth direct readability.