Deformation behavior and failure mechanism during in-phase and out-of-phase thermomechanical fatigue in directionally solidified CM247LC superalloy

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue Pub Date : 2025-09-09 DOI:10.1016/j.ijfatigue.2025.109274

Ranjeet Kumar , Subhrajit Patnaik , Bhagyaraj Jayabalan , Subrata Mukherjee , Ede Hari Krishna , Dibyendu Chatterjee , Kartik Prasad , Sumantra Mandal

{"title":"Deformation behavior and failure mechanism during in-phase and out-of-phase thermomechanical fatigue in directionally solidified CM247LC superalloy","authors":"Ranjeet Kumar , Subhrajit Patnaik , Bhagyaraj Jayabalan , Subrata Mukherjee , Ede Hari Krishna , Dibyendu Chatterjee , Kartik Prasad , Sumantra Mandal","doi":"10.1016/j.ijfatigue.2025.109274","DOIUrl":null,"url":null,"abstract":"<div><div>This work investigates thermomechanical fatigue (TMF) behavior in directionally solidified CM247LC superalloy at the strain amplitude of ± 0.5 % and ± 0.8 % under in-phase (IP) and out-of-phase (OP) conditions in the temperature interval of 573 K ↔ 1143 K. TMF test results reveal that fatigue life significantly reduces under IP condition due to accumulation of greater strain localization attributed to synergistic effect of creep-fatigue-oxidation damage, especially at high strain amplitude. Conversely, under OP condition, fatigue life degrades due to oxidation-fatigue damage and formation of micro-twins, specifically at high strain amplitude. The alloy exhibits hardening followed by softening behavior under IP condition, whereas it shows continuous hardening under OP condition. Initial hardening in all the TMF conditions is associated with dislocation–dislocation and dislocation-precipitate interactions. The softening phenomena under IP condition is attributed to shearing of γ′ precipitates by stacking faults and anti-phase boundary, whereas the hardening phenomena under OP condition is associated with micro-twins, especially at high strain amplitude. Commonly, strain accumulation is found near the MC carbides in all conditions. Fractography analysis substantiates this fact and shows micro-cracks near MC carbides. Additionally, fractography analysis reveals oxide spike under OP condition, where strain localization is significantly high, as evidenced by electron backscatter diffraction analysis.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109274"},"PeriodicalIF":6.8000,"publicationDate":"2025-09-09","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/S0142112325004712","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

This work investigates thermomechanical fatigue (TMF) behavior in directionally solidified CM247LC superalloy at the strain amplitude of ± 0.5 % and ± 0.8 % under in-phase (IP) and out-of-phase (OP) conditions in the temperature interval of 573 K ↔ 1143 K. TMF test results reveal that fatigue life significantly reduces under IP condition due to accumulation of greater strain localization attributed to synergistic effect of creep-fatigue-oxidation damage, especially at high strain amplitude. Conversely, under OP condition, fatigue life degrades due to oxidation-fatigue damage and formation of micro-twins, specifically at high strain amplitude. The alloy exhibits hardening followed by softening behavior under IP condition, whereas it shows continuous hardening under OP condition. Initial hardening in all the TMF conditions is associated with dislocation–dislocation and dislocation-precipitate interactions. The softening phenomena under IP condition is attributed to shearing of γ′ precipitates by stacking faults and anti-phase boundary, whereas the hardening phenomena under OP condition is associated with micro-twins, especially at high strain amplitude. Commonly, strain accumulation is found near the MC carbides in all conditions. Fractography analysis substantiates this fact and shows micro-cracks near MC carbides. Additionally, fractography analysis reveals oxide spike under OP condition, where strain localization is significantly high, as evidenced by electron backscatter diffraction analysis.

Abstract Image

查看原文本刊更多论文

定向凝固CM247LC高温合金相内外热疲劳变形行为及失效机理

本文研究了在573 K↔1143 K时，在同相（IP）和非相（OP）条件下定向凝固的CM247LC高温合金在应变幅为±0.5%和±0.8%时的热机械疲劳行为。TMF试验结果表明，蠕变-疲劳-氧化损伤的协同效应导致了更大的应变局部化，特别是在高应变幅值条件下，疲劳寿命显著降低。相反，在OP条件下，由于氧化疲劳损伤和微孪晶的形成，疲劳寿命下降，特别是在高应变幅下。合金在IP条件下表现为先硬化后软化，而在OP条件下表现为连续硬化。所有TMF条件下的初始硬化都与位错-位错和位错-沉淀相互作用有关。IP条件下的软化现象主要是由于层错和反相边界对γ′相的剪切，而OP条件下的硬化现象主要与微孪晶有关，特别是在高应变幅下。通常，在所有条件下，在MC碳化物附近发现应变积累。断口分析证实了这一事实，并在MC碳化物附近发现了微裂纹。此外，电子背散射衍射分析表明，在OP条件下，断口分析显示氧化峰，应变局部化明显高。

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.