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Barr CM, Duong T, Bufford DC, Milne Z, Molkeri A, Heckman NM, Adams DP, Srivastava A, Hattar K, Demkowicz MJ, Boyce BL. Autonomous healing of fatigue cracks via cold welding. Nature 2023; 620:552-556. [PMID: 37468631 DOI: 10.1038/s41586-023-06223-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/16/2023] [Indexed: 07/21/2023]
Abstract
Fatigue in metals involves gradual failure through incremental propagation of cracks under repetitive mechanical load. In structural applications, fatigue accounts for up to 90% of in-service failure1,2. Prevention of fatigue relies on implementation of large safety factors and inefficient overdesign3. In traditional metallurgical design for fatigue resistance, microstructures are developed to either arrest or slow the progression of cracks. Crack growth is assumed to be irreversible. By contrast, in other material classes, there is a compelling alternative based on latent healing mechanisms and damage reversal4-9. Here, we report that fatigue cracks in pure metals can undergo intrinsic self-healing. We directly observe the early progression of nanoscale fatigue cracks, and as expected, the cracks advance, deflect and arrest at local microstructural barriers. However, unexpectedly, cracks were also observed to heal by a process that can be described as crack flank cold welding induced by a combination of local stress state and grain boundary migration. The premise that fatigue cracks can autonomously heal in metals through local interaction with microstructural features challenges the most fundamental theories on how engineers design and evaluate fatigue life in structural materials. We discuss the implications for fatigue in a variety of service environments.
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Affiliation(s)
- Christopher M Barr
- Sandia National Laboratories, Albuquerque, NM, USA
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, USA
| | - Ta Duong
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA
| | | | - Zachary Milne
- Sandia National Laboratories, Albuquerque, NM, USA
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, USA
| | - Abhilash Molkeri
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA
| | - Nathan M Heckman
- Sandia National Laboratories, Albuquerque, NM, USA
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, USA
| | | | - Ankit Srivastava
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA
| | - Khalid Hattar
- Sandia National Laboratories, Albuquerque, NM, USA
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, USA
- Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, USA
| | - Michael J Demkowicz
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA.
| | - Brad L Boyce
- Sandia National Laboratories, Albuquerque, NM, USA.
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, USA.
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2
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Barrios A, Kunka C, Nogan J, Hattar K, Boyce BL. Automated High-Throughput Fatigue Testing of Freestanding Thin Films. SMALL METHODS 2023:e2201591. [PMID: 37098647 DOI: 10.1002/smtd.202201591] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/21/2023] [Indexed: 06/19/2023]
Abstract
Mechanical testing at small length scales has traditionally been resource-intensive due to difficulties with meticulous sample preparation, exacting load alignments, and precision measurements. Microscale fatigue testing can be particularly challenging due to the time-intensive, tedious repetition of single fatigue experiments. To mitigate these challenges, this work presents a new methodology for the high-throughput fatigue testing of thin films at the microscale. This methodology features a microelectromechanical systems-based Si carrier that can support the simultaneous and independent fatigue testing of an array of samples. To demonstrate this new technique, the microscale fatigue behavior of nanocrystalline Al is efficiently characterized via this Si carrier and automated fatigue testing with in situ scanning electron microscopy. This methodology reduces the total testing time by an order of magnitude, and the high-throughput fatigue results highlight the stochastic nature of the microscale fatigue response. This manuscript also discusses how this initial capability can be adapted to accommodate more samples, different materials, new geometries, and other loading modes.
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Affiliation(s)
- Alejandro Barrios
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA
| | - Cody Kunka
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA
| | - John Nogan
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA
| | - Khalid Hattar
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA
- Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Brad L Boyce
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA
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In-Situ Thermography Investigation of Crack Growth in Armco Iron under Gigacycle Fatigue Loading. METALS 2022. [DOI: 10.3390/met12050870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A non-destructive thermographic methodology based on the temperature field is utilized to determine the crack tip position during the very high cycle fatigue (VHCF) test of pure iron and deduce the corresponding fatigue crack growth rate (FCGR). To this end, a piezoelectric fatigue machine is employed to test 1 mm thick pure iron samples at 20 kHz in push–pull fatigue loading. Two cameras are placed on each side of the plate sample, an infrared one for measuring the temperature fields on the specimen surface and an optical one for visualizing the crack tip verification. The centre section of the specimen is notched to initiate the crack. The temperature field is converted into intrinsic dissipation to quantify the inelastic strain energy according to energy conservation. The maximum value of intrinsic dissipation in each thermal image is related to the position of the crack tip and thus allows monitoring of the crack evolution during the fatigue test. The obtained results show that one specific specimen broke at 7.25 × 107 cycles in the presence of a very low-stress amplitude (122 MPa). It is observed that the intrinsic dissipation has a low-constant level during the initiation and the short cracking, then sharply grows during the long cracking. This transition is visible on the polished surface of the sample, where the plasticity appears during the long cracking and slightly before. The material parameters in the Paris equation obtained from the intrinsic dissipation in the short crack growth are close to the results available in the literature as well as those obtained by the optical camera.
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Abstract
Abstract
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Sun C, Du Z, Nagarajan S, Zhao H, Wen S, Zhao S, Zhang P, Zhang L. Impact of uniaxial tensile fatigue on the evolution of microscopic and mesoscopic structure of carbon black filled natural rubber. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181883. [PMID: 30891299 PMCID: PMC6408415 DOI: 10.1098/rsos.181883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
This investigation addresses the evolution of the microscopic and mesoscopic structures distribution, and micro-defects of carbon black (CB) filled natural rubber (NR) under uniaxial tensile condition during the fatigue process. NR was filled with three different grades of CB in order to understand the impact of the structural degree and specific surface areas of CB and fatigue degree on the Payne effect. It was found that the Payne effect was initially suppressed and then enhanced by increasing the degree of fatigue. The decrease of the storage modulus in the low strain area was attributed to the CB network destruction and the breakdown of the matrix cross-linking network in the early fatigue stage. However, by further increasing the degree of fatigue, the spatial rearrangement of CB aggregates with the orientation of molecular chains between adjacent CB aggregates will results in mechanical reinforcement before the appearance of micro-defects. Moreover, it has been demonstrated that the structural degree of CB has a stronger impact on the mesoscopic structures than the specific surface area of CB during the tensile fatigue process.
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Affiliation(s)
- Chong Sun
- Beijing Engineering Research Center of Advanced Elastomers, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
| | - Zhongjin Du
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
| | - Selvaraj Nagarajan
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
| | - Hongying Zhao
- Institute of Polymer Materials and Plastics Engineering, Clausthal University, Clausthal-Zellerfeld 38678, Germany
| | - Shipeng Wen
- Beijing Engineering Research Center of Advanced Elastomers, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Suhe Zhao
- Beijing Engineering Research Center of Advanced Elastomers, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Ping Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
| | - Liqun Zhang
- Beijing Engineering Research Center of Advanced Elastomers, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
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Barrios A, Gupta S, Castelluccio GM, Pierron ON. Quantitative in Situ SEM High Cycle Fatigue: The Critical Role of Oxygen on Nanoscale-Void-Controlled Nucleation and Propagation of Small Cracks in Ni Microbeams. NANO LETTERS 2018; 18:2595-2602. [PMID: 29489378 DOI: 10.1021/acs.nanolett.8b00343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This Letter presents a quantitative in situ scanning electron microscope (SEM) nanoscale high and very high cycle fatigue (HCF/VHCF) investigation of Ni microbeams under bending, using a MEMS microresonator as an integrated testing machine. The novel technique highlights ultraslow fatigue crack growth (average values down to ∼10-14 m/cycle) that has heretofore not been reported and that indicates a discontinuous process; it also reveals strong environmental effects on fatigue lives that are 3 orders of magnitude longer in a vacuum than in air. This ultraslow fatigue regime does not follow the well documented fatigue mechanisms that rely on the common crack tip stress intensification, mediated by dislocation emission and associated with much larger crack growth rates. Instead, our study reveals fatigue nucleation and propagation mechanisms that mainly result from room temperature void formation based on vacancy condensation processes that are strongly affected by oxygen. This study therefore shows significant size effects governing the bending high/very high cycle fatigue behavior of metals at the micro- and nanoscales, whereby the stress concentration effect at the tip of a growing small fatigue crack is assumed to be greatly reduced by the effect of the bending-induced extreme stress gradients, which prevents any significant cyclic crack tip opening displacement. In this scenario, ultraslow processes relying on vacancy formation at the subsurface or in the vicinity of a crack tip and subsequent condensation into voids become the dominant fatigue mechanisms.
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Affiliation(s)
- Alejandro Barrios
- G.W. Woodruff School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0405 , United States
| | - Saurabh Gupta
- G.W. Woodruff School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0405 , United States
| | | | - Olivier N Pierron
- G.W. Woodruff School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0405 , United States
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McDowell MT, Jungjohann KL, Celano U. Dynamic Nanomaterials Phenomena Investigated with in Situ Transmission Electron Microscopy: A Nano Letters Virtual Issue. NANO LETTERS 2018; 18:657-659. [PMID: 29444554 DOI: 10.1021/acs.nanolett.8b00266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Matthew T McDowell
- G. W. W. School of Mechanical Engineering and School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Katherine L Jungjohann
- Center for Integrated Nanotechnologies, Sandia National Laboratory , Albuquerque, New Mexico 87185, United States
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Luo C, Wang C, Wu X, Zhang J, Chu J. In Situ Transmission Electron Microscopy Characterization and Manipulation of Two-Dimensional Layered Materials beyond Graphene. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1604259. [PMID: 28783241 DOI: 10.1002/smll.201604259] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Two-dimensional (2D) ultra-thin materials beyond graphene with rich physical properties and unique layered structures are promising for applications in electronics, chemistry, energy, and bioscience, etc. The interaction mechanisms among the structures, chemical compositions and physical properties of 2D layered materials are critical for fundamental nanosciences and the practical fabrication of next-generation nanodevices. Transmission electron microscopy (TEM), with its high spatial resolution and versatile external fields, is undoubtedly a powerful tool for the static characterization and dynamic manipulation of nanomaterials and nanodevices at the atomic scale. The rapid development of thin-film and precision microelectromechanical systems (MEMS) techniques allows 2D layered materials and nanodevices to be probed and engineered inside TEM under external stimuli such as thermal, electrical, mechanical, liquid/gas environmental, optical, and magnetic fields at the nanoscale. Such advanced technologies leverage the traditional static TEM characterization into an in situ and interactive manipulation of 2D layered materials without sacrificing the resolution or the high vacuum chamber environment, facilitating exploration of the intrinsic structure-property relationship of 2D layered materials. In this Review, the dynamic properties tailored and observed by the most advanced and unprecedented in situ TEM technology are introduced. The challenges in spatial, time and energy resolution are discussed also.
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Affiliation(s)
- Chen Luo
- Shanghai Key Laboratory of Multidimensional Information Processing, State Key Laboratory of Transducer Technology, Department of Electrical Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Chaolun Wang
- Shanghai Key Laboratory of Multidimensional Information Processing, State Key Laboratory of Transducer Technology, Department of Electrical Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Xing Wu
- Shanghai Key Laboratory of Multidimensional Information Processing, State Key Laboratory of Transducer Technology, Department of Electrical Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Jian Zhang
- Shanghai Key Laboratory of Multidimensional Information Processing, State Key Laboratory of Transducer Technology, Department of Electrical Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Junhao Chu
- Shanghai Key Laboratory of Multidimensional Information Processing, State Key Laboratory of Transducer Technology, Department of Electrical Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
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El-Atwani O, Nathaniel JE, Leff AC, Hattar K, Taheri ML. Direct Observation of Sink-Dependent Defect Evolution in Nanocrystalline Iron under Irradiation. Sci Rep 2017; 7:1836. [PMID: 28500318 PMCID: PMC5432011 DOI: 10.1038/s41598-017-01744-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/30/2017] [Indexed: 11/29/2022] Open
Abstract
Crystal defects generated during irradiation can result in severe changes in morphology and an overall degradation of mechanical properties in a given material. Nanomaterials have been proposed as radiation damage tolerant materials, due to the hypothesis that defect density decreases with grain size refinement due to the increase in grain boundary surface area. The lower defect density should arise from grain boundary-point defect absorption and enhancement of interstitial-vacancy annihilation. In this study, low energy helium ion irradiation on free-standing iron thin films were performed at 573 K. Interstitial loops of a0/2 [111] Burgers vector were directly observed as a result of the displacement damage. Loop density trends with grain size demonstrated an increase in the nanocrystalline (<100 nm) regime, but scattered behavior in the transition from the nanocrystalline to the ultra-fine regime (100–500 nm). To examine the validity of such trends, loop density and area for different grains at various irradiation doses were compared and revealed efficient defect absorption in the nanocrystalline grain size regime, but loop coalescence in the ultra-fine grain size regime. A relationship between the denuded zone formation, a measure of grain boundary absorption efficiency, grain size, grain boundary type and misorientation angle is determined.
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Affiliation(s)
- O El-Atwani
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA, USA. .,Materials Science and Technology Division (MST-8), Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - J E Nathaniel
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA, USA
| | - A C Leff
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA, USA
| | - K Hattar
- Department of Radiation Solid Interactions, Sandia National Laboratories, Albuquerque, NM, USA
| | - M L Taheri
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA, USA.
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