摘要
针对航空航天等高精尖领域亟待解决的金属增材制造过程冶金质量在线实时检测与评价问题,概述了金属增材制造超声在线检测技术的国内外研究现状及进展;重点介绍了自主研制激光超声多冶金特征同步在线检测系统的设计原理及组成;并采用该系统对激光增材制造工件组织晶粒度及表面缺陷特征进行检测试验研究。首先基于激光超声纵波回波信号中心频率偏移实现了激光熔融沉积TC4/B4C复合材料中具有择优晶体取向的粗大α相晶粒团簇尺寸的定量评价;随后对激光熔融沉积AlSi10Mg铝合金表面缺陷进行检测,对扫描检测幅面内各测量点进行多次激励求平均,并结合改进小波阈值和变分模态分解两步降噪处理提高在线实时检测信号信噪比,基于表面波信号能量变化实现了0.5 mm孔洞和0.5 mm宽水平裂纹的可视化成像。
It is urgent and important for online detection and evaluation of metallurgical quality during metal additive manufacturing in the aerospace field.The research status and progress of online ultrasonic testing technology of metal additive manufacturing at home and abroad were summarized.The design principle and the composition of the self-developed laser ultrasonic multi-metallurgical feature synchronous online detection system were introduced.The laser ultrasonic testing experiments were conducted using the self-developed system for the components manufactured by laser additive manufacturing.The size of coarse clusters ofα-phase grains with preferred crystal orientation in laser melting deposited TC_(4)/B_(4)C composites was quantitatively evaluated based on the spectral centroid frequency shift of laser ultrasonic longitudinal wave pulse echoes.Then,the surface defects of laser melting deposited AlSi10Mg aluminum alloy were detected.The signal-to-noise ratio of the online real-time detection signal was improved by combining two methods.First,multiple laser pulses were excited at each measuring point in the scanning detection for averaging.Second,the twostep denoising method by combining the improved wavelet threshold and with variational mode decomposition was used.Based on the energy variation of surface wave pulse signals,the hole with a diameter of 0.5 mm and the horizontal crack with the width of 0.5 mm were imaged.
作者
白雪
马健
许万卫
王贺
BAI Xue;MA Jian;XU Wanwei;WANG He(Laser Institute,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250104,China)
出处
《航空制造技术》
CSCD
北大核心
2022年第20期70-82,共13页
Aeronautical Manufacturing Technology
基金
国家自然科学基金(51805304)
山东省重大科技创新工程项目(2019JZZY010418)
山东大学高校20条自主培养创新团队项目(2020GXRC004)
齐鲁工业大学(山东省科学院)计算机科学与技术学科基础研究加强项目(2021JC02008)
中国铁道科学研究院集团有限公司科研项目(2020YJ096)。
关键词
金属增材制造
激光超声
在线检测
晶粒度表征
缺陷成像
Metal additive manufacturing(MAM)
Laser ultrasonic
Online testing
Grain size characterization
Defect imaging
