{"title":"Elucidating the mechanisms of gradient nanostructure on enhancing fatigue resistance of pure zirconium","authors":"Yuliang Zhou , Conghui Zhang , Xiangkang Zeng , Wenguang Zhu , Kangkai Song","doi":"10.1016/j.matchar.2025.114844","DOIUrl":null,"url":null,"abstract":"<div><div>In this paper, the strengthening mechanism and anti-fatigue mechanism of gradient nanostructure were discussed in detail, and a crack propagation rate model was established based on the characterization of gradient nanostructure and residual compressive stress. Results indicated that the gradient nanostructure exhibited several characteristics, including grain size, grain orientation, twin thickness/density, dislocation density gradient, and residual stress gradient. The strengthening effect mainly originates from nanograins/ultra-fined grains and twins. Compared with coarse-grained Zr (CG-Zr), the fatigue limit of gradient nanostructured Zr (GNS-Zr) was increased by about 25 %. The synergistic effect of gradient nanostructure and residual compressive stress enhances the resistance of crack initiation, effectively reducing the driving force and increasing the resistance of crack propagation, finally significantly improving the fatigue lifetime of GNS-Zr. A crack propagation rate model with gradient nanostructured characteristics was obtained.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114844"},"PeriodicalIF":4.8000,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Characterization","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1044580325001330","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CHARACTERIZATION & TESTING","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, the strengthening mechanism and anti-fatigue mechanism of gradient nanostructure were discussed in detail, and a crack propagation rate model was established based on the characterization of gradient nanostructure and residual compressive stress. Results indicated that the gradient nanostructure exhibited several characteristics, including grain size, grain orientation, twin thickness/density, dislocation density gradient, and residual stress gradient. The strengthening effect mainly originates from nanograins/ultra-fined grains and twins. Compared with coarse-grained Zr (CG-Zr), the fatigue limit of gradient nanostructured Zr (GNS-Zr) was increased by about 25 %. The synergistic effect of gradient nanostructure and residual compressive stress enhances the resistance of crack initiation, effectively reducing the driving force and increasing the resistance of crack propagation, finally significantly improving the fatigue lifetime of GNS-Zr. A crack propagation rate model with gradient nanostructured characteristics was obtained.
期刊介绍:
Materials Characterization features original articles and state-of-the-art reviews on theoretical and practical aspects of the structure and behaviour of materials.
The Journal focuses on all characterization techniques, including all forms of microscopy (light, electron, acoustic, etc.,) and analysis (especially microanalysis and surface analytical techniques). Developments in both this wide range of techniques and their application to the quantification of the microstructure of materials are essential facets of the Journal.
The Journal provides the Materials Scientist/Engineer with up-to-date information on many types of materials with an underlying theme of explaining the behavior of materials using novel approaches. Materials covered by the journal include:
Metals & Alloys
Ceramics
Nanomaterials
Biomedical materials
Optical materials
Composites
Natural Materials.