基于非线性超声的SLM制备车用合金疲劳损伤检测  

Fatigue damage detection of SLM alloy based on nonlinear ultrasonic

作　　者：贾广辉[1] 袁留奎[1] 常浩 张昊[3] JIA Guanghui;YUAN Liukui;CHANG Hao;ZHANG Hao(School of Automobile,Henan Vocational and Technical College of Communications,Zhengzhou 450000,CHN;Vehicle Development Department,Dongfeng SUV Co.,Ltd.,Wuhan 430056,CHN;School of Instrument Science and Engineering,Southeast University,Nanjing 210096,CHN)

机构地区：[1]河南交通职业技术学院汽车学院,河南郑州450000 [2]东风越野车有限公司整车开发部,湖北武汉430056 [3]东南大学仪器科学与工程学院,江苏南京210096

出　　处：《制造技术与机床》2023年第3期184-188,共5页Manufacturing Technology & Machine Tool

基　　金：河南省高等学校青年骨干教师培养计划项目(2016GGJS-248)。

摘　　要：为了提高对车用选区激光熔融GH4169镍基合金疲劳损伤的检测能力,设计了一种基于非线性超声的高效检测方法。根据超声非线性系数精确判断试件的疲劳损伤状态,并通过高次谐波检测技术快速测定合金疲劳损伤。研究结果表明:二次谐波与基波相比形成了更低幅值。与初始试件相比,经过18 000次疲劳测试后,试样形成了更大变化幅值信号。试样组织中形成了等轴晶形态,大部分柱状晶表现出较强方向性。周期疲劳试样形成了大量疲劳裂纹。增加疲劳周期后,非线性超声测试变化不断增大,形成了相近的变化特征。与缩颈处测试点相比,喇叭口处测试点超声非线性系数跟疲劳周数之间虽然也呈现正相关的特点,但只发生了小幅增长。该研究对提高激光熔融试样的疲劳损伤检测精度具有很好的理论支撑价值。In order to improve the detection ability of fatigue damage of selective laser melting GH4169 nickelbased alloy for vehicle, an efficient detection method based on nonlinear ultrasound was designed. The fatigue damage state of the specimen was accurately judged according to the nonlinear coefficient of ultrasound, and the fatigue damage of the alloy was rapidly measured by the high-order harmonic detection technology. Results show that the second harmonic wave has a lower amplitude than the fundamental wave. The specimen after 20, 000 fatigue tests shows signals with a larger amplitude of change in comparison to the initial specimen. Equiaxed crystals are formed in the microstructure of the sample, and most of the columnar crystals show strong directivity. A large number of fatigue cracks appear in the periodic fatigue samples. With the increase of fatigue period, the variation of nonlinear ultrasonic test is enlarged, forming similar variation characteristics. Compared with the test point at the neck contraction, the ultrasonic nonlinear coefficient at the horn mouth has a positive correlation with the fatigue cycle, but it only increases slightly. This study has a good theoretical support value for improving the fatigue damage detection accuracy of laser fused samples.

关 键 词：非线性超声 选择性激光熔化 疲劳损伤 疲劳周期 二次谐波 

分 类 号：TB551[理学—物理]