Different fatigue crack propagation resistance anisotropy of Al-Li alloy cold-rolled sheet and hot-rolled plate

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue Pub Date : 2025-08-27 DOI:10.1016/j.ijfatigue.2025.109256

Guang-jun Zeng , Jin-feng Li , Zhen-zhen Liu , Tian-le Liu , Hua Zhou , Bao Qi , Yi-ming Guo , Tian-yu Peng , Peng-cheng Ma , Yong-lai Chen

{"title":"Different fatigue crack propagation resistance anisotropy of Al-Li alloy cold-rolled sheet and hot-rolled plate","authors":"Guang-jun Zeng , Jin-feng Li , Zhen-zhen Liu , Tian-le Liu , Hua Zhou , Bao Qi , Yi-ming Guo , Tian-yu Peng , Peng-cheng Ma , Yong-lai Chen","doi":"10.1016/j.ijfatigue.2025.109256","DOIUrl":null,"url":null,"abstract":"<div><div>The fatigue crack propagation (FCP) resistance anisotropy of Al-Li alloy cold-rolled (CR) sheets and hot-rolled (HR) plates was systematically investigated through the integrated microstructural and crystallographic analysis. By employing the equivalent slip system number (<em>ESSN</em>) as a novel metric to quantify crack path tortuosity and slip activity. It was revealed that the T8-aged CR and HR samples showed higher strength along rolling direction (RD) due to their higher crystallographic orientation factor. Notably, the <em>ESSN</em> value of T8-aged CR sample along the transverse-longitudinal (TL) direction was higher than that of the longitudinal–transverse (LT) direction, which facilitated readily activation of slip systems within grains for transgranular crack propagation in CR-TL sample. Consequently, the CR-TL samples presented more tortuous crack paths with pronounced crack branching and enhanced FCP resistance compared to CR-LT samples. In contrast, the HR-LT sample demonstrated superior FCP resistance compared to HR-TL, CR-TL and CR-LT samples, which was primarily related to the blocking effect at grain boundaries and sub-grain zones. The sub-grain zones promoted microcrack formation, while the finer T<sub>1</sub> precipitates within the sub-grain zones were more susceptible to multi-step sheared by dislocations, collectively contributing to the enhanced FCP resistance in HR-LT samples.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"202 ","pages":"Article 109256"},"PeriodicalIF":6.8000,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fatigue","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0142112325004530","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}

引用次数: 0

Abstract

The fatigue crack propagation (FCP) resistance anisotropy of Al-Li alloy cold-rolled (CR) sheets and hot-rolled (HR) plates was systematically investigated through the integrated microstructural and crystallographic analysis. By employing the equivalent slip system number (ESSN) as a novel metric to quantify crack path tortuosity and slip activity. It was revealed that the T8-aged CR and HR samples showed higher strength along rolling direction (RD) due to their higher crystallographic orientation factor. Notably, the ESSN value of T8-aged CR sample along the transverse-longitudinal (TL) direction was higher than that of the longitudinal–transverse (LT) direction, which facilitated readily activation of slip systems within grains for transgranular crack propagation in CR-TL sample. Consequently, the CR-TL samples presented more tortuous crack paths with pronounced crack branching and enhanced FCP resistance compared to CR-LT samples. In contrast, the HR-LT sample demonstrated superior FCP resistance compared to HR-TL, CR-TL and CR-LT samples, which was primarily related to the blocking effect at grain boundaries and sub-grain zones. The sub-grain zones promoted microcrack formation, while the finer T₁ precipitates within the sub-grain zones were more susceptible to multi-step sheared by dislocations, collectively contributing to the enhanced FCP resistance in HR-LT samples.

查看原文本刊更多论文

铝锂合金冷轧薄板与热轧薄板抗疲劳裂纹扩展各向异性的差异

通过显微组织和晶体学的综合分析，系统地研究了铝锂合金冷轧薄板和热轧薄板的抗疲劳裂纹扩展（FCP）各向异性。采用等效滑移系统数（ESSN）作为量化裂纹路径弯曲度和滑移活度的新指标。结果表明，t8时效的CR和HR由于具有较高的晶体取向因子，在轧制方向上表现出较高的强度。值得注意的是，t8时效CR试样沿横向-纵向（TL）方向的ESSN值高于纵向-横向（LT）方向的ESSN值，这有利于CR-TL试样晶粒内滑移系统的激活，从而促进穿晶裂纹扩展。结果表明，与CR-LT相比，CR-TL试样的裂纹路径更为曲折，裂纹分支明显，抗FCP能力增强。相比之下，HR-LT样品比HR-TL、CR-TL和CR-LT样品表现出更强的FCP抗性，这主要与晶界和亚晶带的阻断效应有关。亚晶区促进了微裂纹的形成，而亚晶区内较细的T1相更容易受到位错的多步剪切，共同促进了HR-LT样品抗FCP能力的增强。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

International Journal of Fatigue 工程技术-材料科学：综合

CiteScore

10.70

自引率

21.70%

发文量

619

审稿时长

58 days

期刊介绍： Typical subjects discussed in International Journal of Fatigue address: Novel fatigue testing and characterization methods (new kinds of fatigue tests, critical evaluation of existing methods, in situ measurement of fatigue degradation, non-contact field measurements) Multiaxial fatigue and complex loading effects of materials and structures, exploring state-of-the-art concepts in degradation under cyclic loading Fatigue in the very high cycle regime, including failure mode transitions from surface to subsurface, effects of surface treatment, processing, and loading conditions Modeling (including degradation processes and related driving forces, multiscale/multi-resolution methods, computational hierarchical and concurrent methods for coupled component and material responses, novel methods for notch root analysis, fracture mechanics, damage mechanics, crack growth kinetics, life prediction and durability, and prediction of stochastic fatigue behavior reflecting microstructure and service conditions) Models for early stages of fatigue crack formation and growth that explicitly consider microstructure and relevant materials science aspects Understanding the influence or manufacturing and processing route on fatigue degradation, and embedding this understanding in more predictive schemes for mitigation and design against fatigue Prognosis and damage state awareness (including sensors, monitoring, methodology, interactive control, accelerated methods, data interpretation) Applications of technologies associated with fatigue and their implications for structural integrity and reliability. This includes issues related to design, operation and maintenance, i.e., life cycle engineering Smart materials and structures that can sense and mitigate fatigue degradation Fatigue of devices and structures at small scales, including effects of process route and surfaces/interfaces.