{"title":"刀具预热对无润滑油添加剂搅拌摩擦沉积修复AA7050飞机紧固件孔疲劳行为的影响","authors":"I.Y. Hidalgo , V.A. Rojas , N.I. Palya , N. Zhu , L.N. Brewer , G.W. Kubacki , P.G. Allison , J.B. Jordon","doi":"10.1016/j.ijfatigue.2025.109272","DOIUrl":null,"url":null,"abstract":"<div><div>This study demonstrates the successful repair of fastener holes in AA7050-T7451 plates using twin-rod additive friction stir deposition (TR-AFSD), a solid-state additive manufacturing technology. Oversized holes surrounded by blend-out regions, simulating the removal of corrosion-damaged areas that are commonly found around fastener holes, were repaired via TR-AFSD using the same AA7050 feedstock materials without any pre-sprayed graphite lubricant. Two repair strategies were evaluated: Repair Methodology A (RM-A), where the tool directly engages the substrate, and Repair Methodology B (RM-B), which incorporates a preheating dwell on a sacrificial plate to enable instantaneous material flow upon deposition. RM-B reached the peak axial forge force (26.16 kN) faster than RM-A, thereby enhancing volumetric filling and densification. Optical and electron microscopy revealed defect-free, metallurgically bonded interfaces, while cross-sectional hardness profiles showed no significant differences between the two repair methodologies. Under tension–tension (R = 0.1) fatigue loading at a 25 MPa constant stress amplitude, samples repaired with RM-B achieved an average fatigue life of 27,918 ± 2,817 cycles, compared to 24,800 ± 1,766 cycles for unrepaired, oversized controls. These results highlight the novelty and effectiveness of TR-AFSD in restoring structural integrity and improving fatigue resistance in aerospace-grade aluminum components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109272"},"PeriodicalIF":6.8000,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of tool pre-heating on the fatigue behavior of lubricant-free additive friction stir deposition repairs of AA7050 aircraft fastener holes\",\"authors\":\"I.Y. Hidalgo , V.A. Rojas , N.I. Palya , N. Zhu , L.N. Brewer , G.W. Kubacki , P.G. Allison , J.B. Jordon\",\"doi\":\"10.1016/j.ijfatigue.2025.109272\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This study demonstrates the successful repair of fastener holes in AA7050-T7451 plates using twin-rod additive friction stir deposition (TR-AFSD), a solid-state additive manufacturing technology. Oversized holes surrounded by blend-out regions, simulating the removal of corrosion-damaged areas that are commonly found around fastener holes, were repaired via TR-AFSD using the same AA7050 feedstock materials without any pre-sprayed graphite lubricant. Two repair strategies were evaluated: Repair Methodology A (RM-A), where the tool directly engages the substrate, and Repair Methodology B (RM-B), which incorporates a preheating dwell on a sacrificial plate to enable instantaneous material flow upon deposition. RM-B reached the peak axial forge force (26.16 kN) faster than RM-A, thereby enhancing volumetric filling and densification. Optical and electron microscopy revealed defect-free, metallurgically bonded interfaces, while cross-sectional hardness profiles showed no significant differences between the two repair methodologies. Under tension–tension (R = 0.1) fatigue loading at a 25 MPa constant stress amplitude, samples repaired with RM-B achieved an average fatigue life of 27,918 ± 2,817 cycles, compared to 24,800 ± 1,766 cycles for unrepaired, oversized controls. These results highlight the novelty and effectiveness of TR-AFSD in restoring structural integrity and improving fatigue resistance in aerospace-grade aluminum components.</div></div>\",\"PeriodicalId\":14112,\"journal\":{\"name\":\"International Journal of Fatigue\",\"volume\":\"203 \",\"pages\":\"Article 109272\"},\"PeriodicalIF\":6.8000,\"publicationDate\":\"2025-09-08\",\"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/S0142112325004694\",\"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}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fatigue","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0142112325004694","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}
Effect of tool pre-heating on the fatigue behavior of lubricant-free additive friction stir deposition repairs of AA7050 aircraft fastener holes
This study demonstrates the successful repair of fastener holes in AA7050-T7451 plates using twin-rod additive friction stir deposition (TR-AFSD), a solid-state additive manufacturing technology. Oversized holes surrounded by blend-out regions, simulating the removal of corrosion-damaged areas that are commonly found around fastener holes, were repaired via TR-AFSD using the same AA7050 feedstock materials without any pre-sprayed graphite lubricant. Two repair strategies were evaluated: Repair Methodology A (RM-A), where the tool directly engages the substrate, and Repair Methodology B (RM-B), which incorporates a preheating dwell on a sacrificial plate to enable instantaneous material flow upon deposition. RM-B reached the peak axial forge force (26.16 kN) faster than RM-A, thereby enhancing volumetric filling and densification. Optical and electron microscopy revealed defect-free, metallurgically bonded interfaces, while cross-sectional hardness profiles showed no significant differences between the two repair methodologies. Under tension–tension (R = 0.1) fatigue loading at a 25 MPa constant stress amplitude, samples repaired with RM-B achieved an average fatigue life of 27,918 ± 2,817 cycles, compared to 24,800 ± 1,766 cycles for unrepaired, oversized controls. These results highlight the novelty and effectiveness of TR-AFSD in restoring structural integrity and improving fatigue resistance in aerospace-grade aluminum components.
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.