作者：张斌¹, 于润桥², 刘怡², 胡博²

作者单位：1. 中国航空制造技术研究院检测中心，北京 100024;
2. 南昌航空大学 无损检测教育部重点实验室，江西 南昌 330063

关键词：弱磁检测;扩散焊缺陷;拉依达准测;磁感应强度

摘要：

针对60 mm厚钛合金扩散焊中未焊合和紧贴型微小缺陷，提出一种新的钛合金扩散焊弱磁检测方法。利用基于弱磁原理的固相焊缝检测系统采集试件表面弱磁信号，分析扩散焊不同缺陷的磁信号特征。结果表明：弱磁方法可检测出埋深60 mm，厚度0.02 mm未焊合缺陷和直径0.01 mm紧贴型缺陷，可根据表面磁感应强度和磁感应强度梯度信号判断缺陷位置。磁异常幅值、磁异常宽度和基于拉依达准则的磁梯度阈值可作为识别缺陷类型的磁信号特征量，可有效判别出钛合金扩散焊中的未焊合和紧贴型微小缺陷。弱磁检测技术在大厚度钛合金扩散焊微小缺陷的无损评估中具有可行性。

Experimental study on micromagnetic detection of micro defects in titanium alloy diffusion bonding
ZHANG Bin¹, YU Runqiao², LIU Yi², HU Bo²
1. Testing Center of AVIC Manufacturing Technology Institute, Beijing 100024, China;
2. Key Laboratory of Nondestructive Testing of Ministry of Education, Nanchang Hangkong University, Nanchang 330063, China
Abstract: A new method of micromagnetic detection for diffusion bonding of 60 mm thick titanium alloy was proposed to characterize the tiny defects of non-bonding and kiss-bonding. A solid-state welding detection system based on the principle of micromagnetic field is used to collect the magnetic signal on the surface of specimens. The magnetic signal characteristics of different defects in diffusion bonding were analyzed. The results show that micromagnetic method can detect non-bonding defects of 0.02 mm thickness and kiss-bonding defects of 0.01 mm diameter at 60 mm depth. The defect location can be preliminarily determined according to the surface magnetic induction intensity and its gradient. The magnitude and the width of magnetic anomalies as well as the threshold of magnetic gradient based on pauta criterion can be used as the characteristic parameters to identify the types of defects, which can effectively identify the tiny defects of non-bonding and kiss-bonding in diffusion welding of titanium alloys. The technology of micromagnetic detection is feasible in nondestructive evaluation of tiny defects in diffusion bonding of titanium alloy with large thickness.
Keywords: micromagnetic detection;diffusion bonding defects;pauta criterion;magnetic induction intensity
2020, 46(3):6-11  收稿日期: 2019-05-01;收到修改稿日期: 2019-06-21
基金项目: 国家自然科学基金资助项目（51765048）
作者简介: 张斌(1969-),男,陕西韩城市人,高级工程师,主要从事无损检测技术研究
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