材料工程2026，Vol.54Issue(4)：258-268,11.DOI:10.11868/j.issn.1001-4381.2024.000256
循环载荷下激光选区熔化TC4合金小裂纹萌生与扩展行为
Small crack initiation and propagation behavior of selective laser melting TC4 alloy under cyclic loading
摘要
Abstract
Based on the in-situ fatigue test technique of scanning electron microscope(SEM),the small crack behavior of selective laser melting(SLM)TC4 alloy is studied.The focused ion beam(FIB)technique is used to manufacture the simulative initial defects in the process of additive manufacturing,and the initiation and propagation behavior of small cracks induced by defects are observed under cyclic loading.The results show that under cyclic loading,small cracks are easy to initiate at the surface defect,and the crack fatigue initiation life is short.The fatigue life of SLM TC4 alloys is mainly consumed in the small crack propagation stage.Affected by the microstructure,the small cracks are more likely to propagate along the α/β interface.Due to the random orientation of α laths,the path of small cracks is deflected several times in the initial propagation stage,exhibiting a mixed mode of propagation along α lamellae and through α lamellae within grains,resulting in significant scatter in crack growth rates.At the stable crack propagation stage,the plastic slips of the crack tip are obvious,the influence of microstructure is reduced,and the propagation path tends to straighten.Comparative analysis with long crack growth data indicates that SLM TC4 alloy exhibits a significant"small crack effect".关键词
激光选区熔化/TC4合金/小裂纹效应/裂纹萌生与扩展Key words
selective laser melting/TC4 alloy/small crack effect/crack initiation and propagation分类
矿业与冶金引用本文复制引用
武亮亮,许瑞达,焦泽辉,于慧臣..循环载荷下激光选区熔化TC4合金小裂纹萌生与扩展行为[J].材料工程,2026,54(4):258-268,11.基金项目
中国航发科技创新平台项目(CXPT-2023-035) （CXPT-2023-035）
财政部稳定支持基础研究计划基金项目(KZ0C190727) （KZ0C190727）
