摘要
基于信号分析方法,对采用瑞利波无损表征电刷镀层厚度的方法进行了试验研究。采用中心频率为5MHz,声程固定不变的一发一收模式的双瑞利波探头对不同厚度的电刷镀层试样进行检测,并在互相关函数的基础上计算了由镀层厚度改变而引起的信号间时间差。结果表明,随着镀层厚度的增加,瑞利波在其中的传播速度逐渐变小;随着互相关函数步长n值的增加,互相关函数值的精度逐渐变高,当n值为1时,参考函数长度最佳;镀层厚度-时间差结果符合幂函数变化规律,验证结果表明,采用该方法可实现电刷镀层厚度的无损表征,但镀层的平整度是影响表征结果精度的重要因素。
Based on signal analysis method, the nondestructive characterization method of thickness measurement of brush electro-plating coating with Rayleigh wave was investigated. Two Rayleigh wave transducers with 5 MHz frequency, the distance between which was invariant, were employed as an emitter and a receiver, and the difference in time of flight caused by thickness of coating change was calculated. Results show that the propagation velocity of Rayleigh wave in brush electro-plating coating decreases gradually as the thickness of coating increasing. The accuracy of cross correlation function is improved as the length of reference signal increasing, one cycle is the optimal length as reference function length. The relation of coating thickness and the difference in time of flight is agree with power function, and verification result indicates that thickness of brush electro-plating coating can be evaluated by this method and the smoothness of coating surface is a vital factor for accuracy of thickness measurement of brush electro-plating coating.
作者
盖晓东
胡庆贤
Gai Xiaodong;Hu Qingxian(Xiamen Special Equipment Inspection Institute Xiamen 361004;Jiangsu University of Science and Technology Material Science and Engineering Zhenjiang 212003)
出处
《中国特种设备安全》
2018年第6期52-56,共5页
China Special Equipment Safety
基金
国家质量监督检验检疫总局科技计划项目(编号:2014QK024)
关键词
瑞利波
电刷镀层
互相关函数
无损表征
Rayleigh wave
Brush electro-plating coating
Cross correlation function
Nondestructive characterization
