Development of Micro Tensile Testing Method in an FIB System for Evaluating Grain Boundary Strength

Fujii, K.; Fukuya, Koji

doi:10.2320/matertrans.m2010320

Cited by 32 publications

(14 citation statements)

References 9 publications

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“…The instrumentation required for such approach has not been available until very recently and the first results have started appearing in the literature. [91,132] It was shown that, through a multifaceted approach, individual grain boundaries oxidized during exposure to simulated pressurized nuclear reactor cooling water, can be mechanically tested and their resistance to fracture can be quantified. These results can have direct consequences in understanding the mechanisms controlling SCC propagation and initiation.…”

Section: E Micromechanical Testingmentioning

confidence: 99%

“…This is particularly interesting when the GB in question is oxidized, allowing the determination of the stress required to fracture the oxidized GB and thus providing the necessary data to validate/ disprove SIO mechanisms. Fujii and Fukuya [132] devised a very ingenious way of measuring these stresses by devising a micro-tensile experiment inside a FIB. He found that stresses as low as 300 MPa could fracture Alloy 600 oxidized grain boundaries.…”

Section: Grain Boundary Strengthmentioning

confidence: 99%

See 1 more Smart Citation

SCC in PWRs: Learning from a Bottom-Up Approach

Lozano-Pérez

Dohr

Meisnar

et al. 2014

Metallurgical and Materials Transactions E

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Stress corrosion cracking (SCC) of steels and Ni-base alloys in the pressurized water reactor (PWR) primary circuit has been a cause for reactor outages for many decades. Although the nuclear industry has made a considerable research effort to understand and predict SCC in this system, this enterprise is complicated by the sheer number of interdependent variables that have a major influence on the degradation behavior. SCC is highly time-dependant and often only sets in after many years. Therefore, autoclave testing, even with accelerating conditions, is an expensive and time-consuming endeavor. However, the results collected by a great number of research groups over many years have identified the most important parameters and, in many cases, how they influence the degradation behavior. The community has been constantly working on the development of a general theory that encompasses the underlying mechanisms and is capable of describing and predicting the observed degradation behavior. In the last two decades, the focus of research has shifted from the traditional approach of autoclave testing (for susceptibility and crack growth rates) to high-resolution microscopy and chemical analysis. The newly available techniques are providing data on chemical and structural changes locally at the crack tip where SCC occurs. The techniques covered in this review can provide very high chemical sensitivity at atomic resolution, which is ultimately needed in the quest for a generalized theory.

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Section: E Micromechanical Testingmentioning

confidence: 99%

Section: Grain Boundary Strengthmentioning

confidence: 99%

SCC in PWRs: Learning from a Bottom-Up Approach

Lozano-Pérez

Dohr

Meisnar

et al. 2014

Metallurgical and Materials Transactions E

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“…Whereas SAGBO mechanism involves cracking of an already oxidized grain boundary ahead of crack tip . In high temperature and high‐pressure environment, grain boundary strength after oxidation is significantly lower to that when grain boundary is not oxidized, reduction in grain boundary strength leads to increase in CGR and the material is more prone to cracking.…”

Section: Discussionmentioning

confidence: 99%

Environmentally assisted crack growth rate of an austenitic steel TP347HFG in high‐temperature medium

Khan

Zhang

Yue

et al. 2017

Materials & Corrosion

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The crack growth rate (CGR) tests of austenitic steel TP347HFG were conducted under <10‐8000 ppb dissolved oxygen (DO) in steam, the alternating environment of air and steam and supercritical water (SCW) at 600–650 °C. A constant stress intensity factor (K) method and direct current potential drop technique were used in the tests to evaluate its environmentally assisted cracking (EAC) properties as superheater and reheater boiler tubes in ultra‐supercritical power plants. CGR increases monotonically with temperature and DO content. CGR in SCW is greater than that in the high‐temperature steam which indicates that exposure pressure has an obvious effect on crack propagation. The varying CGR in different experimental environments show that exposure medium participates in the cracking process. Fracture surface and cross‐sectional surface of compact tension specimen were analyzed by scanning electron microscope. The mechanism of crack propagation in different exposure environment is further discussed.

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“…Details of the micro-tensile test procedure have been reported elsewhere [20]. SIM images from a microtensile test are shown in Fig.…”

Section: Micro-tensile Testsmentioning

confidence: 99%

“…The bending tests would be suitable for brittle materials, but not for ductile materials because most ductile materials do not fracture by bending. Fujii and Fukuya [20] have reported a micro-tensile testing method for micron-sized specimens with a GB; the specimens are prepared by FIB micro-processing. They have applied a load on the specimens in FIB system using a micro-cantilever and discussed fracture behavior of phosphorus segregated GB in Fe-Mn-P alloy.…”

Section: Introductionmentioning

confidence: 99%