摘要
在超声检测过程中,材料的表面粗糙度越大,越容易使得有用的超声信号被淹没在复杂的背景噪声中,造成缺陷等特征信息难以被有效识别。因此,提出一种基于频谱能量差的材料表面超声成像修正方法。该方法以表面粗糙度小的超声信号作为模板,比较表面粗糙度大的超声信号与该模板信号的频谱差异,并将该差异值补偿到受表面粗糙度影响较大的超声信号中去,以减少材料表面粗糙度对超声检测结果的影响。利用超声显微镜对无间隙原子钢的表面进行超声检测,获得材料表面的超声成像,通过对修正前后的结果进行比较,验证了新方法的有效性。
In the process of ultrasonic test,the larger the surface roughness of material is,the easier the ultrasonic signal is buried in the complex background noises. So the defects and other feature information are difficult to be identified effectively. A correction method for ultrasonic imaging of material surface based on spectral energy difference is proposed. In the method,the ultrasonic signals of material with small surface roughness are used as a template signal. A value of spectral energy difference is calculated by comparing the template signal and ultrasonic signals of material with large roughness. In order to reduce the effects of surface roughness on the ultrasonic test results,the value is used as compensation for the ultrasonic signals that are strongly influenced by the rough surface. Ultrasonic imaging of material surface is obtained by utilizing the ultrasonic microscope to measure the interstitial-free steel. The effectiveness of the proposed method is proved by comparing the results before and after the correction.
出处
《工程与试验》
2016年第3期1-5,48,共6页
Engineering and Test
基金
国家自然科学基金资助项目(No.51575038)
关键词
超声成像
表面粗糙度
频谱能量差
超声显微镜
ultrasonic imaging
surface roughness
spectral energy difference
acoustic microscope
