激光选区熔化成形不锈钢板材内部缺陷无损检测可靠性分析  

Reliability analysis on non-destructive testing for internal defects of stainless steel sheet formed by laser selective melting

作　　者：刘春华[1] 门正兴[2] 李艳丽[3] 陈晓辉[1] 张宏 Liu Chunhua;Men Zhengxing;Li Yanli;Chen Xiaohui;Zhang Hong(Facility Design and Testing Technology Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China;Mechanical and Electrical Engineering Department,Chengdu Aeronautic Polytechnic,Chengdu 610021,China;Materials Engineering Department,Sichuan Engineering Technical College,Deyang 618000,China;Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province,College of Architecture and Environment,Sichuan University,Chengdu 610065,China)

机构地区：[1]中国空气动力研究与发展中心设备设计与测试技术研究所,四川绵阳621000 [2]成都航空职业技术学院机电工程学院,四川成都610021 [3]四川工程职业技术学院材料工程系,四川德阳618000 [4]四川大学建筑与环境学院破坏力学与工程防灾减灾四川省重点实验室,四川成都610065

出　　处：《锻压技术》2023年第7期212-221,共10页Forging & Stamping Technology

基　　金：国家自然科学基金面上项目(12272245);四川省应用基础研究项目(2022NSFSC0324);四川大学-自贡政府战略合作支持项目(2019CDZG-4)。

摘　　要：为验证不同无损检测方法对激光选区熔化(SLM)成形不锈钢材料内部缺陷检测的适应性,分别采用X射线数字成像检测(DR)、工业计算机层析成像检测(CT)、相控阵超声检测(PAUT)和超声检测(UT)等对SLM成形不锈钢梯形板(厚度为11~20 mm)开展检测。实验结果表明:CT的灵敏度最高,能够检测出15.58μm的内部自然孔隙缺陷,达到了10μm级;PA及直接接触法UT可以检测出毫米级的面积型缺陷;DR对SLM不锈钢梯形板面积型缺陷不敏感。另外,水浸法UT结果表明,通过提升探头频率来提高UT的灵敏度是比较有限的,探头频率超过10 MHz即难以实施有效检测。金相分析结果验证了CT、PA和UT的可靠性,SLM不锈钢梯形板中存在直径为Φ20~Φ100μm的单独气孔和裂纹缺陷,同时也存在局部区域1 mm左右的密集型缺陷。In order to verify the adaptability of different non-destructive testing methods to the detection of internal defects for stainless steel materials formed by selective laser melting(SLM),the SLM formed stainless steel trapezoidal plate(thickness of 11-20 mm)was tested by X-ray digital radiogrophy(DR),industrial computed tomography(CT)testing,phased array ultrasonic testing(PAUT),and ultrasonic testing(UT),etc.The experimental results show that CT has the highest sensitivity and can detect internal natural pore defects of 15.58μm,reaching the level of 10μm.PA and direct contact method UT can detect millimeter-scale area defects.DR is not sensitive to area defects of SLM stainless steel trapezoidal sheet.In addition,the results of the water immersion method UT show that it is relatively limited to improve the sensitivity of UT by increasing the probe frequency,and it is difficult to implement effective detection when the probe frequency exceeds 10 MHz.The metallographic analysis results verify the reliability of CT,PA and UT.There are individual pores with the diameter ofΦ20-Φ100μm and defect cracks in the SLM stainless steel trapezoidal sheet,and there are also dense defects of about 1 mm in the local area.

关 键 词：激光选区熔化 304L不锈钢 内部缺陷 无损检测 适应性 

分 类 号：TG316[金属学及工艺—金属压力加工]