{"title":"Enhancing fatigue performance of AA6063-T6 fasteners through novel electromagnetic cold expansion using a double-frequency discharge","authors":"","doi":"10.1016/j.engfracmech.2024.110509","DOIUrl":null,"url":null,"abstract":"<div><p>Non-contact electromagnetic cold expansion process (EMCE) represents a highly promising way to enhance the fatigue performance of fasteners. However, within the current technological framework, the necessity for dual power supplies and an accurate discharge control system has constrained the development and application of this technique. To address this, a novel EMCE process utilizing a double-frequency discharge is proposed. This process is accompanied by the development of an electromagnetic system with only one set of power supply to generate a current composed of a gradual-ascending and rapid-descending stage. This current induces a significant radially outward Lorentz force, facilitating hole expansion and introducing residual compressive stress around the hole, thus increasing the fatigue life of the fasteners. The experimental results demonstrate a remarkable enhancement in fatigue life for samples treated with the EMCE process when compared to untreated ones, showing an impressive 6.8-fold, 4.9-fold, and 1.6-fold increase at stress loads of 120 MPa, 130 MPa, and 150 MPa, respectively. Microstructural analysis reveals that the processed components exhibit favorable surface integrity, and there is no significant grain refinement near the hole. Moreover, it is found that there existed optimal current waveform to maximize fatigue life. These findings hold significance in understanding the EMCE process and advancing its practical applicability.</p></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":null,"pages":null},"PeriodicalIF":4.7000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Engineering Fracture Mechanics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0013794424006726","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
Non-contact electromagnetic cold expansion process (EMCE) represents a highly promising way to enhance the fatigue performance of fasteners. However, within the current technological framework, the necessity for dual power supplies and an accurate discharge control system has constrained the development and application of this technique. To address this, a novel EMCE process utilizing a double-frequency discharge is proposed. This process is accompanied by the development of an electromagnetic system with only one set of power supply to generate a current composed of a gradual-ascending and rapid-descending stage. This current induces a significant radially outward Lorentz force, facilitating hole expansion and introducing residual compressive stress around the hole, thus increasing the fatigue life of the fasteners. The experimental results demonstrate a remarkable enhancement in fatigue life for samples treated with the EMCE process when compared to untreated ones, showing an impressive 6.8-fold, 4.9-fold, and 1.6-fold increase at stress loads of 120 MPa, 130 MPa, and 150 MPa, respectively. Microstructural analysis reveals that the processed components exhibit favorable surface integrity, and there is no significant grain refinement near the hole. Moreover, it is found that there existed optimal current waveform to maximize fatigue life. These findings hold significance in understanding the EMCE process and advancing its practical applicability.
期刊介绍:
EFM covers a broad range of topics in fracture mechanics to be of interest and use to both researchers and practitioners. Contributions are welcome which address the fracture behavior of conventional engineering material systems as well as newly emerging material systems. Contributions on developments in the areas of mechanics and materials science strongly related to fracture mechanics are also welcome. Papers on fatigue are welcome if they treat the fatigue process using the methods of fracture mechanics.