Article
Engineering, Mechanical
Cheng Luo, Huang Yuan
Summary: This study investigated the thermomechanical fatigue behavior of nickel-base single-crystal superalloy with different crystal orientations. The crack initiation modes and damage mechanisms were characterized using SEM and optical microscopy. In IP-TMF, creep damage originated from casting pores and propagated under mode I. The creep facets were influenced by activated slip systems, while fatigue damage depended on crystal orientation and developed by slipping along different crystallographic planes. In OP-TMF tests, oxidation-assisted cracking was non-crystallographic for all crystal orientations, with the crack growing within the oxidized material.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Pengfei Wang, Xinbao Zhao, Quanzhao Yue, Wanshun Xia, Qingqing Ding, Hongbin Bei, Yuefeng Gu, Xiao Wei, Ze Zhang
Summary: In this study, the fatigue-damaged microstructures of Ni-based single-crystal superalloys were compared under cyclic deformation at 800 and 900 degrees C using electron microscopy. The relationship between microstructure and mechanical properties was investigated, and it was found that with increasing temperature, deformation was more concentrated in the y matrix channels and cyclic deformation behavior stabilized. Additionally, the importance of interfacial dislocation networks in enhancing cyclic stability and hindering cyclic tension-compression asymmetry was discussed.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Mechanical
Wen-Ping Wu, Zi-Jun Ding, Yun-Li Li, Chao Yu, Guozheng Kang
Summary: The thermomechanical fatigue (TMF) properties of Ni-based single crystal superalloys are studied using molecular dynamics simulations. Two different cyclic deformation mechanisms are identified. Under Out-of-phase TMF loading, the samples exhibit a higher cyclic stress range, plastic strain energy density, and shorter fatigue life compared to In-phase TMF loading. The low-temperature tension half-cycle is found to result in earlier failure due to dislocation and stacking fault penetration into the precipitate phase, attracting more attention in actual operation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Nanoscience & Nanotechnology
Sean P. Murray, Alice Cervellon, Jonathan Cormier, Tresa M. Pollock
Summary: Research shows that fatigue crack initiation is mainly influenced by oxidation-assisted surface cracking in air, while the fatigue performance improves under vacuum due to the presence of internal casting pores. Additionally, recrystallized regions on the fracture surfaces of both alloys in the vacuum test condition have been identified, which was not previously reported for single crystal Ni-base alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Crystallography
Pengfei Wang, Xinbao Zhao, Quanzhao Yue, Wanshun Xia, Qingqing Ding, Hongbin Bei, Yuefeng Gu, Yuefei Zhang, Ze Zhang
Summary: Total strain-control, low-cycle fatigue experiments were conducted on a fourth-generation Ni-based single-crystal superalloy at 980 degrees C. Fracture morphologies and dislocation characteristics of the samples were determined using scanning electron microscopy and transmission electron microscopy. The increase in strain amplitude led to higher cyclic stress and plastic strain per cycle, as well as a decrease in cyclic lifetime. The presence of interfacial dislocation networks and accumulated dislocations contributed to cyclic hardening and softening, respectively. Furthermore, the strain amplitude affected the location and number of crack initiation sites and secondary cracks.
Article
Engineering, Mechanical
Zihao Tan, Xinguang Wang, Yongmei Li, Yanhong Yang, Yunling Du, Zhicheng Ge, Jide Liu, Jinlai Liu, Jinguo Li, Yizhou Zhou, Xiaofeng Sun
Summary: In this study, out-of-phase thermal-mechanical fatigue experiments were conducted to investigate the behavior, deformation, and damage mechanisms of the fourth-generation SX superalloy. The results revealed that at low strain ranges, TMF life was mainly influenced by high-temperature oxidation, while at higher strain ranges, fatigue cracks were predominantly initiated from severe plastic deformation. This study provides valuable guidance for further application of fourth-generation SX superalloys.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Wen Jiang, Piao Li, Wei-Xing Yao, Shao-Shi Rui, Hui-Ji Shi, Jie Huang
Summary: In this study, the high-cycle fatigue (HCF) lives and fatigue limits of nickel-based single crystal superalloys (NBSX) with different porosity sizes were investigated. It was found that the critical pore size plays a crucial role in determining the HCF properties. Additionally, the initiation of secondary cracks from the oxide layer was observed, which further weakens the HCF properties. A life prediction model based on the critical plane parameter and oxidation kinetic equation was proposed to evaluate the effect of porosity size and oxidation on the HCF life of NBSX. Furthermore, a fatigue limit evaluation model combining the life prediction model and Murakami model was presented. The accuracy and effectiveness of the models were verified through comparison with test results. Lastly, the defect-tolerance analysis using the Kitagawa-Takahashi diagram provided valuable insights for anti-fatigue design of NBSX.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
C. H. Wu, R. Jiang, L. C. Zhang, Y. C. Wang, Y. Chen, Y. D. Song
Summary: This study investigates the fatigue crack growth (FCG) mechanisms of Ni-based superalloy FGH4098 at temperatures ranging from 650 to 800 degrees Celsius. The results show that the FCG rate increases by 2-3 orders of magnitude with increased temperature and prolonged dwell time, which is attributed to grain boundary oxidation. Characterization of the crack tips reveals that deformation, such as dislocations and stacking faults, mainly occurs within the gamma channel, accompanied by a change in grain orientation due to severe deformation. Pre-formed oxides at uncracked grain boundaries facilitate the FCG process. A mechanism map of the interaction between deformation-assisted grain boundary oxidation and FCG is proposed.
Article
Chemistry, Physical
Stephen Okhiai Emokpaire, Nan Wang, Jide Liu, Chongwei Zhu, Xinguang Wang, Jinguo Li, Yizhou Zhou
Summary: This study investigates the effect of Ru element on the γ'-phase evolution and deformation mechanism in a fourth-generation Ni-based single-crystal superalloy. The results show that Ru element alters the distribution coefficient of other elements in the alloy, leading to a difference in microstructure compared to the alloy without Ru. Ru addition triggers the incubation period before primary creep stage and inhibits the slip system {111}<112> at medium-temperature and high-stress creep, resulting in a considerably low creep rate and high creep life for the Ru-containing alloy.
Article
Materials Science, Multidisciplinary
Bin Hu, Yanling Pei, Shengkai Gong, Shusuo Li
Summary: The study on high cycle fatigue testing of a Ni-based superalloy shows that orientation deviation significantly affects fatigue properties, with the best fatigue life appearing on precise orientation. As orientation deviation increases, the fatigue properties of the alloy degenerate significantly.
Article
Materials Science, Multidisciplinary
Wei Xiong, Zaiwang Huang, Guang Xie, Zhicheng Ge, Xin Wang, Yuzhang Lu, Wei Zheng, Langhong Lou, Jian Zhang
Summary: A series of experiments were conducted to investigate the effect of deformation temperature on the recrystallization of nickel-based single crystal superalloys. The results showed that the recrystallization features varied with different temperature ranges and were influenced by different dislocation features and slip systems. The critical kernel average misorientation for inducing recrystallization was found to be approximately 0.4 degrees. The number of recrystallized grains was proportional to the average misorientation.
MATERIALS & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Qinjia Wang, Yidong Wu, Jinbin Chen, Jinxia Song, Chengbo Xiao, Xidong Hui
Summary: The roles of minor elements in single crystal superalloys' fatigue properties have been overlooked, but our study found that carbon (C) and boron (B) significantly increased stress amplitude and reduced cyclic hysteresis energy under the condition of approximate low cycle fatigue (LCF) lifetime at 980 degrees C. The enhanced fatigue stress is believed to be associated with interstitial solid solution strengthening. The improved fatigue deformation resistance is attributed to the formation of slip bands and <010> superdislocations in C-containing alloys, while B additions led to denser dislocation-tangle at the gamma/gamma' interface and homogenization of overall dislocation distribution.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Wen-Ping Wu, Zi-Jun Ding, Bin Chen, Hong-Fei Shen, Yun-Li Li
Summary: This study investigates the effects of rhenium (Re) on low cycle fatigue behaviors and deformation mechanisms of Ni-based single crystal superalloys using molecular dynamics simulations. The results show that the addition of Re improves the low cycle fatigue behaviors and enhances the plastic deformation resistance of the superalloys. The cyclic deformation mechanism is strongly influenced by temperature.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Nanoscience & Nanotechnology
Abbas Jamali, Anxin Ma, Javier LLorca
Summary: The analysis of a textured AZ31B-O Mg alloy subjected to fully-reversed, strain-controlled cyclic deformation revealed that pyramidal slip and twinning coexisted in only 9.1% of the grains after 50 cycles, while cracking was widespread, with grain boundary cracks found in approximately 15% of small grains and transgranular cracks in large grains after 50 cycles.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Abbas Jamali, Anxin Ma, Javier LLorca
Summary: The deformation and fatigue crack nucleation mechanisms in a textured AZ31B-O Mg alloy were investigated using slip trace analysis and secondary electron microscopy. The results showed that the localization of deformation in different grains led to the nucleation of fatigue cracks along specific slip bands or twin boundaries. Grain boundary cracks were present in all cases but were not critical for fatigue failure. This study provides valuable information for evaluating the influence of microstructural features on the fatigue life of Mg alloys and for simulating their fatigue behavior using fatigue indicator parameters.
Article
Materials Science, Multidisciplinary
Mikael Segersall, Paraskevas Kontis, Stella Pedrazzini, Paul A. J. Bagot, Michael P. Moody, Johan J. Moverare, Roger C. Reed
Article
Nanoscience & Nanotechnology
Mikael Segersall, Daniel Leidermark, Johan J. Moverare
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2015)
Article
Materials Science, Multidisciplinary
Paraskevas Kontis, Zhuangming Li, Mikael Segersall, Johan J. Moverare, Roger C. Reed, Dierk Raabe, Baptiste Gault
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2018)
Article
Materials Science, Multidisciplinary
Daniel Leidermark, Mikael Segersall
COMPUTATIONAL MATERIALS SCIENCE
(2014)
Article
Materials Science, Multidisciplinary
Mikael Segersall, Johan J. Moverare, Daniel Leidermark, Kjell Simonsson
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2014)
Article
Chemistry, Physical
Mikael Segersall, Johan J. Moverare
Article
Engineering, Mechanical
Mikael Segersall, Annie Kerwin, Alex Hardaker, Magnus Kahlin, Johan Moverare
Summary: This study investigated the fatigue properties of Ti-6Al-4V produced by electron beam powder bed fusion with different wall thicknesses and orientations. Specimens at 90 degrees direction exhibited worse fatigue life, and the fatigue strength was lower for thin samples compared to thicker ones. Considering surface roughness in stress level calculations reduced or eliminated the influence of specimen thickness.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Zhicheng Ge, Guang Xie, Mikael Segersall, Viktor Norman, Zhe Chen, Johan Moverare, Langhong Lou, Jian Zhang
Summary: The deformation mechanisms of a single crystal nickel-base superalloy with and without Ru-doped have been investigated under out-of-phase thermomechanical fatigue. It was found that the Ru-doped alloy exhibits a longer thermomechanical fatigue life and different deformation mechanisms compared to the Ru-free alloy.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Frans Palmert, David Gustafsson, Per Almroth, Henrik Petersson, Mikael Segersall, Johan Moverare
Summary: This article focuses on the prediction of fatigue life of single crystal gas turbine blades, particularly the uncertainty of rapid crystallographic crack growth along the close-packed planes. A criterion is proposed to predict the transition from mode I to crystallographic crack growth, which is essential for accurately predicting the number of cycles from crack initiation to the onset of crystallographic crack growth. The proposed criterion is calibrated through various tests representative of gas turbine blades, including isothermal fatigue crack growth tests and thermomechanical fatigue crack growth tests with hold times and pre-test aging.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Mechanics
Stefan B. Lindstrom, Hannes Wemming, Zlatan Kapidzic, Mohamed S. Loukil, Mikael Segersall
Summary: In this study, the in-plane, linear-elastic material parameters of carbon fiber-reinforced polymer (CFRP) plates are identified using integrated digital image correlation (IDIC) method with gradient-free optimization. A monolithic least-squares problem is formulated based on the video capture of a tension/compression test, where the material parameters are treated as unknowns. The use of holeplate specimens induces transverse deformations, allowing for the identification of all parameters with one tensile test. Furthermore, we demonstrate the enhanced robustness of IDIC characterization by employing an invariant-based CFRP model parameterized by the Tsai modulus.
COMPOSITE STRUCTURES
(2023)
Article
Chemistry, Physical
Jialiang Chen, Jinghao Xu, Mikael Segersaell, Eduard Hryha, Ru Lin Peng, Johan Moverare
Summary: This study investigated the effects of powder reuse on the mechanical performance of a nickel-based superalloy. It was found that metallic oxides with increased oxygen content were present on the surface of the reused powders. Negligible deterioration in strength and tensile ductility was observed, while there was some scatter in fatigue performance with regard to fatigue life. Deformation and fatigue crack propagation mechanisms were discussed to describe the effects of powder degradation.
Article
Engineering, Mechanical
Ahmed Azeez, Daniel Leidermark, Mikael Segersall, Robert Eriksson
Summary: In warm pre-stressing (WPS), the fracture resistance of cracked steel components is increased under certain temperature-load histories. This beneficial effect of WPS improves safety margins and can potentially extend fatigue life. However, understanding and predicting the WPS effects are crucial for utilizing these benefits.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Proceedings Paper
Engineering, Mechanical
Mikael Segersall, Johan J. Moverare, Daniel Leidermark, Kjell Simonsson
11TH INTERNATIONAL FATIGUE CONGRESS, PTS 1 AND 2
(2014)
Proceedings Paper
Engineering, Mechanical
Daniel Leidermark, Mikael Segersall, Johan Moverare, Kjell Simonsson
11TH INTERNATIONAL FATIGUE CONGRESS, PTS 1 AND 2
(2014)
Article
Engineering, Mechanical
Miloslav Kepka, Miloslav Kepka Jr, Radovan Minich
Summary: This paper focuses on the fatigue life evaluation of the bodywork of a new articulated electric (battery) bus. The findings resulted in recommendations to improve the operational reliability of a particular vehicle and provided challenges for future research.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
T. Dusautoir, B. Berthel, S. Fouvry, P. Matzen, K-D. Meck
Summary: This study investigates the impact of post-processing treatments on the fatigue limit of additive manufactured Ti-6Al-4V under stress gradients, with a focus on surface integrity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhuofan Xia, Di Wu, Xiaochen Zhang, Jianqiu Wang, En -Hou Han
Summary: The study reveals the surface-initiated rolling contact fatigue (RCF) failure mechanism under heavy load and initial high roughness surface. The results indicate that precursor of collapsed morphology and nanocrystalline layer are the main factors causing lower RCF life with high roughness compared to low roughness surfaces. The spalling failure initiating from low roughness surface under heavy load is strongly dependent on surface plastic deformation.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Daniel Gren, Knut Andreas Meyer
Summary: Rolling contact loading can cause plastic deformation and fatigue cracks. Current rail standards do not consider the effect of plasticity on mechanical behavior. This study proposes a new method for evaluating the fatigue life of deformed material and finds that superimposed compressive axial loads can increase fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
R. Kumar, S. Sanyal, J. Bhagyaraj, E. Hari Krishna, S. Mukherjee, K. Prasad, S. Mandal
Summary: This study investigates the thermomechanical fatigue (TMF) behavior of Timetal 834 alloy under different loading conditions. The results show that the alloy exhibits different cyclic hardening and softening responses at different strain amplitudes. The strain amplitude and phase angle have significant effects on the TMF life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kai Donnerbauer, Tobias Bill, Peter Starke, Ruth Acosta, Bharath Yerrapa, Christian Boller, Klaus Heckmann, Frank Walther
Summary: Given the aging of nuclear power plants, it is important to develop methods for evaluating the integrity of components and structures in nuclear engineering. Suitable nondestructive testing methods can detect material degradation and determine its fatigue life. This study utilized various NDT parameters and scanning electron microscopic methods to explore the relationship between microstructure evolution and NDT data.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Liuyong He, Jiang Zheng, Tianjiao Li, Houkun Zhou, Lihong Xia, Bin Jiang
Summary: This study quantitatively analyzed the effects of precipitates on the deformation mode, cracking mode, and mechanical behavior of WE54 magnesium alloy during low-cycle fatigue. It was found that precipitates promoted the activation of dislocation slip and suppressed the activation of twinning, affecting the cracking mode and mechanical behavior.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Xiangkang Zeng, Conghui Zhang, Wenguang Zhu, Mingliang Zhu, Tongguang Zhai, Xiaomei He, Kangkai Song, Zhuohang Xie
Summary: The cyclic deformation behaviors and damage mechanisms of pure Zr were investigated. The cyclic stress response was mainly influenced by substructure evolutions. Prismatic < a > dislocation slip was identified as the dominant deformation mechanism. Fatigue damage was not only influenced by the initial texture, but also other factors.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Jingyu Yang, Bingbing Li, Yiming Zheng, Gang Chen, Xu Chen
Summary: Heat treatment is used to improve the low-cycle fatigue performance of additive manufactured 316LN stainless steel. The heat-treated material demonstrates initially cyclic hardening followed by softening behavior, and shows a stronger resistance to crack propagation compared to the as-built material, resulting in a longer fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Lang Zou, Dongfang Zeng, Xiong Chen, Jun Li, Hai Zhao, Liantao Lu
Summary: This study investigates the competitive relationship between fretting fatigue and plain fatigue in press-fitted railway axles. By changing the depth of the stress relief groove, the plain fatigue limit and fretting fatigue strength were tested. Detailed information was gathered, and an evaluation methodology integrating finite element simulation and the Modified Wohler Curve Method was established. The study concludes that the optimal groove depth, which balances the anti-fatigue capabilities, depends on the number of test cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Davide Leonetti, Koji Kinoshita, Yukina Takai, Alain Nussbaumer
Summary: This paper investigates the fatigue behavior of non-load-carrying transverse welded steel attachments, including fatigue crack monitoring and fracture surface analysis under constant and variable amplitude loading. A procedure is proposed to obtain a Markov transition matrix based on the measured strain signal and to randomly resample the stress history for variable amplitude fatigue tests.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhe Zhang, Bing Yang, Yuedong Wang, Shoune Xiao
Summary: This paper presents a method for designing fatigue life prediction models with small sample sizes by handling limited sample data. The method integrates the equivalent structural stress method with the maximum likelihood estimation method and adds reliability verification, resulting in enhanced goodness of fit, stability, and optimized sample quantity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Cooper K. Hansen, Gary F. Whelan, Jacob D. Hochhalter
Summary: This paper presents a method to address the computational demand issue of computing FIPs using CPFEM by developing an interpretable machine learning model. Genetic programming is used to evolve interpretable expressions of FIPs from microstructure features, and these models can serve as efficient substitutes for CPFEM and be easily integrated into engineering workflows.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Luca Susmel
Summary: This paper discusses the problem of estimating notch fatigue limits using machine learning. The results show that machine learning is a promising approach for designing notched components against fatigue. The accuracy in estimating the fatigue limit can be increased by increasing the size and quality of the calibration dataset, as well as including additional input features.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kefeng Gao, Guoqi Tan, Yanyan Liu, Qiang Wang, Qian Tang, Xuegang Wang, Qiqiang Duan, Zengqian Liu, Zhe Yi, Zhefeng Zhang
Summary: Bioinspired architectures have significant effects on material enhancement. This study investigates the fatigue properties of bioinspired ceramic-polymer composites and natural nacre, revealing the close relationship between architectural types, orientations, fatigue performance, and damage mechanisms.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
