摘要
基于超声回波技术研究了等离子喷涂涂层的声学特性,采用浮力法获得了涂层的孔隙率。通过频率谱分析法对超声波在涂层中传播的理论进行了推导,建立了能够表征涂层特性的传递函数H(f),由传递函数获取了超声波在涂层中传播的速度、涂层界面的反射系数、密度、衰减系数等声学参量。经分析表明,涂层的声学参量能够反映涂层的质量。分别建立了涂层孔隙率与涂层界面的反射系数、声速、衰减系数的关系,结果表明,随着孔隙率的增加,衰减系数和反射系数增大,相反声速减小。
Acoustic characteristics of plasma sprayed coating are studied with the ultrasonic testing. Porosities of the coatings are tested by buoyancy method. The analytic equation of ultrasonic propagation in the coating based on spectrum analysis is deduced. A transfer function H（y3 is established, which contains information on the acoustic properties of the coating. Not only the ultrasonic propagation velocity in the coating, but also reflec- tion coefficient, attenuation coefficient, density of the coating can be acquired. It is found that these parameters mentioned above can characterize physical property of the coating. The relationships between porosity and re- flection coefficient, sound velocity, attenuation coefficient are investigated respectively. The results show that re- flection coefficient and attenuation coefficient increase with the increase of porosity of the coating. The sound velocity decreases with the increase of porosity. The method is suitable for the evaluation of the coating quality.
出处
《测控技术》
CSCD
北大核心
2012年第10期124-127,132,共5页
Measurement & Control Technology
关键词
超声检测
孔隙率
声速
反射系数
衰减系数
：ultrasonic testing
porosity
sound velocity
reflection coefficient
attenuation coefficient
