CAJ | 학술논문

基于超声波在介质中的传播理论，在当量法基础上采用超声波对激光熔覆层表层裂纹深度进行定量评价。结果表明：表层裂纹信号幅值随裂纹深度的增大而增大，当裂纹深度达到1.0 mm时，信号幅值基本保持不变。相同深度表层裂纹超声波信号幅值随检测距离增大而减小，并趋于平缓，分析认为激光熔覆层中各向异性树枝晶组织及层间界面导致声波能量衰减是引起上述结果的主要原因。结合上述研究结果，本研究对激光熔覆层组织引起的声波能量衰减进行补偿，进而实现表层裂纹深度定量评价方法的修正，在一定程度上提高了激光熔覆层表层裂纹深度的评价精度。
기우초성파재개질중적전파이론，재당량법기출상채용초성파대격광용복층표층렬문심도진행정량평개。결과표명：표층렬문신호폭치수렬문심도적증대이증대，당렬문심도체도1.0 mm시，신호폭치기본보지불변。상동심도표층렬문초성파신호폭치수검측거리증대이감소，병추우평완，분석인위격광용복층중각향이성수지정조직급층간계면도치성파능량쇠감시인기상술결과적주요원인。결합상술연구결과，본연구대격광용복층조직인기적성파능량쇠감진행보상，진이실현표층렬문심도정량평개방법적수정，재일정정도상제고료격광용복층표층렬문심도적평개정도。
Based on the propagation theory of ultrasonic wave in medium and the equivalent method, quantitative evaluation of surface crack depth in laser cladding coating was studied. The results show that ultrasonic wave signal amplitude of surface crack increases gradually with crack depth increasing. After crack depth attains 1. 0 mm, signal amplitude of surface crack nearly keeps stable as crack depth increases further. For the same depth, ultrasonic wave signal amplitude of surface crack decreases gradually as detection distance of ultrasonic wave increases, and signal amplitude tends to be stable further. It is assumed that ultrasonic wave energy attenuation caused by anisotropic microstructure and layer interface of laser cladding coating is the main reason for the above results. In order to improve surface crack depth evaluation accuracy, ultrasonic wave energy attenuation caused by microstructure of laser cladding coating is compensated, and the modified approach for surface crack depth of laser cladding coating is proposed and studied.