Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures

This study aims to explore the effect of microstructural parameters on the notch fatigue damage behavior of the TC21 alloy. Different levels of lamellar microstructures were achieved through distinct aging temperatures of 550 °C, 600 °C, and 650 °C. The findings reveal that increasing aging temperat...

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Main Authors: Xiaosong Zhou, Xiang Li, Chaowen Huang, Quan Wu, Fei Zhao
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Metals
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Online Access:https://www.mdpi.com/2075-4701/15/1/18
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author Xiaosong Zhou
Xiang Li
Chaowen Huang
Quan Wu
Fei Zhao
author_facet Xiaosong Zhou
Xiang Li
Chaowen Huang
Quan Wu
Fei Zhao
author_sort Xiaosong Zhou
collection DOAJ
description This study aims to explore the effect of microstructural parameters on the notch fatigue damage behavior of the TC21 alloy. Different levels of lamellar microstructures were achieved through distinct aging temperatures of 550 °C, 600 °C, and 650 °C. The findings reveal that increasing aging temperature primarily contributes to the augmentation of α colony (α<sub>c</sub>) thickness, grain boundaries α phase (GBα) thickness, and α fine (α<sub>fine</sub>) size alongside a reduction in α lath (α<sub>lath</sub>) thickness and α<sub>fine</sub> content. The notch alters stress distribution and relaxation effects at the root, enhancing notched tensile strength while weakening plasticity. Moreover, the increased thickness of GBα emerges as a critical factor leading to the increase area of intergranular cleavage fracture. It is noteworthy that more thickness α<sub>lath</sub> and smaller α<sub>fine</sub> facilitate deformation coordination and enhance dislocation accumulation at the interface, leading to a higher propensity for micro-voids and micro-cracks to propagate along the interface. Conversely, at elevated aging temperatures, thinner α<sub>lath</sub> and larger α<sub>fine</sub> are more susceptible to fracture, resulting in the liberation of dislocations at the interface. The reduction in α<sub>lath</sub> thickness is crucial for triggering the initiation of multi-system dislocations at the interface, which promotes the development of persistent slip bands (PSBs) and dislocation nets within α<sub>lath</sub>. This phenomenon induces inhomogeneous plastic deformation and localized hardening, fostering the formation of micro-voids and micro-cracks.
format Article
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institution Kabale University
issn 2075-4701
language English
publishDate 2024-12-01
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spelling doaj-art-906d282995be4f258338470dc6e43b312025-01-24T13:41:25ZengMDPI AGMetals2075-47012024-12-011511810.3390/met15010018Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar MicrostructuresXiaosong Zhou0Xiang Li1Chaowen Huang2Quan Wu3Fei Zhao4School of Mechanical and Electrical Engineering, Guizhou Normal University, Guiyang 550025, ChinaCollege of Materials and Metallurgy, Guizhou University, Guiyang 550025, ChinaCollege of Materials and Metallurgy, Guizhou University, Guiyang 550025, ChinaSchool of Mechanical and Electrical Engineering, Guizhou Normal University, Guiyang 550025, ChinaCollege of Materials and Metallurgy, Guizhou University, Guiyang 550025, ChinaThis study aims to explore the effect of microstructural parameters on the notch fatigue damage behavior of the TC21 alloy. Different levels of lamellar microstructures were achieved through distinct aging temperatures of 550 °C, 600 °C, and 650 °C. The findings reveal that increasing aging temperature primarily contributes to the augmentation of α colony (α<sub>c</sub>) thickness, grain boundaries α phase (GBα) thickness, and α fine (α<sub>fine</sub>) size alongside a reduction in α lath (α<sub>lath</sub>) thickness and α<sub>fine</sub> content. The notch alters stress distribution and relaxation effects at the root, enhancing notched tensile strength while weakening plasticity. Moreover, the increased thickness of GBα emerges as a critical factor leading to the increase area of intergranular cleavage fracture. It is noteworthy that more thickness α<sub>lath</sub> and smaller α<sub>fine</sub> facilitate deformation coordination and enhance dislocation accumulation at the interface, leading to a higher propensity for micro-voids and micro-cracks to propagate along the interface. Conversely, at elevated aging temperatures, thinner α<sub>lath</sub> and larger α<sub>fine</sub> are more susceptible to fracture, resulting in the liberation of dislocations at the interface. The reduction in α<sub>lath</sub> thickness is crucial for triggering the initiation of multi-system dislocations at the interface, which promotes the development of persistent slip bands (PSBs) and dislocation nets within α<sub>lath</sub>. This phenomenon induces inhomogeneous plastic deformation and localized hardening, fostering the formation of micro-voids and micro-cracks.https://www.mdpi.com/2075-4701/15/1/18TC21 alloymultilevel lamellar microstructurenotch tensile and high cycle fatiguedamage evolution mechanism
spellingShingle Xiaosong Zhou
Xiang Li
Chaowen Huang
Quan Wu
Fei Zhao
Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
Metals
TC21 alloy
multilevel lamellar microstructure
notch tensile and high cycle fatigue
damage evolution mechanism
title Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
title_full Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
title_fullStr Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
title_full_unstemmed Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
title_short Notch Fatigue Damage Evolution Mechanism of TC21 Alloy with Multilevel Lamellar Microstructures
title_sort notch fatigue damage evolution mechanism of tc21 alloy with multilevel lamellar microstructures
topic TC21 alloy
multilevel lamellar microstructure
notch tensile and high cycle fatigue
damage evolution mechanism
url https://www.mdpi.com/2075-4701/15/1/18
work_keys_str_mv AT xiaosongzhou notchfatiguedamageevolutionmechanismoftc21alloywithmultilevellamellarmicrostructures
AT xiangli notchfatiguedamageevolutionmechanismoftc21alloywithmultilevellamellarmicrostructures
AT chaowenhuang notchfatiguedamageevolutionmechanismoftc21alloywithmultilevellamellarmicrostructures
AT quanwu notchfatiguedamageevolutionmechanismoftc21alloywithmultilevellamellarmicrostructures
AT feizhao notchfatiguedamageevolutionmechanismoftc21alloywithmultilevellamellarmicrostructures