scholarly journals Investigation of microstructure changes in Al2O3-YSZ coatings and YSZ coatings and their effect on thermal cycle life

2022 ◽  
Vol 11 (2) ◽  
pp. 345-353
Author(s):  
Meiqi Dai ◽  
Xuemei Song ◽  
Chucheng Lin ◽  
Ziwei Liu ◽  
Wei Zheng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Cycle ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Crack Size ◽  
Cycle Life ◽  
Atmospheric Plasma ◽  
Microstructure Changes ◽  
Coating Microstructure ◽  
Backscatter Diffraction

AbstractYttria-stabilized zirconia (YSZ) coatings and Al2O3-YSZ coatings were prepared by atmospheric plasma spraying (APS). Their microstructural changes during thermal cycling were investigated via scanning electron microscopy (SEM) equipped with electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). It was found that the microstructure and microstructure changes of the two coatings were different, including crystallinity, grain orientation, phase, and phase transition. These differences are closely related to the thermal cycle life of the coatings. There is a relationship between crystallinity and crack size. Changes in grain orientation are related to microscopic strain and cracks. Phase transition is the direct cause of coating failure. In this study, the relationship between the changes in the coating microstructure and the thermal cycle life is discussed in detail. The failure mechanism of the coating was comprehensively analyzed from a microscopic perspective.

scholarly journals Investigation of microstructure changes in Al2O3-YSZ coatings and YSZ coatings and their effect on thermal cycle life

2021 ◽  
Author(s):  
Meiqi Dai ◽  
Xuemei Song ◽  
Chucheng Lin ◽  
Ziwei Liu ◽  
Wei Zheng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Cycle ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Crack Size ◽  
Cycle Life ◽  
Atmospheric Plasma ◽  
Microstructure Changes ◽  
Coating Microstructure ◽  
Backscatter Diffraction

Abstract Yttria-stabilized zirconia (YSZ) coatings and Al2O3-YSZ coatings were prepared by atmospheric plasma spraying (APS). Their microstructural changes during thermal cycling were investigated via scanning electron microscopy (SEM) equipped with electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). It was found that the microstructure and microstructure changes of the two coatings were different, including crystallinity, grain orientation, phase, and phase transition. These differences are closely related to the thermal cycle life of the coating. There is a relationship between crystallinity and crack size. Changes in grain orientation are related to microscopic strain and cracks. Phase transition is the direct cause of coating failure. In this study, the relationship between the changes in the coating microstructure and the thermal cycle life is discussed in detail. The failure mechanism of the coating was comprehensively analyzed from a microscopic perspective.

Electron backscatter diffraction determination of grain orientation and constituent phases

1999 ◽  
Vol 4 (2) ◽  
pp. 174-174
Author(s):  
Chen Xiaomei ◽  
Liu Jing ◽  
Wang Jianbo ◽  
Zhang Ruikang ◽  
Wang Dahai ◽  
...  
Keyword(s):  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Diffraction Determination ◽  
Electron Backscatter ◽  
Backscatter Diffraction

scholarly journals ARPGE: a computer program to automatically reconstruct the parent grains from electron backscatter diffraction data

2007 ◽  
Vol 40 (6) ◽  
pp. 1183-1188 ◽  
Author(s):  
Cyril Cayron
Keyword(s):  
Phase Transition ◽  
Computer Program ◽  
Diffraction Data ◽  
Electron Backscatter Diffraction ◽  
Parent Phase ◽  
Martensitic Transformations ◽  
Variant Selection ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Theoretical Results

A computer program calledARPGEwritten in Python uses the theoretical results generated by the computer programGenOVato automatically reconstruct the parent grains from electron backscatter diffraction data obtained on phase transition materials with or without residual parent phase. The misorientations between daughter grains are identified with operators, the daughter grains are identified with indexed variants, the orientations of the parent grains are determined, and some statistics on the variants and operators are established. Some examples with martensitic transformations in iron and titanium alloys were treated. Variant selection phenomena were revealed.

Electron backscatter diffraction investigation of local misorientations and orientation gradients in connection with evolution of grain boundary structures in deformed and annealed zirconium. A new approach in grain boundary analysis

2013 ◽  
Vol 46 (2) ◽  
pp. 483-492 ◽  
Author(s):  
Mariusz Jedrychowski ◽  
Jacek Tarasiuk ◽  
Brigitte Bacroix ◽  
Sebastian Wronski
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Lattice Defect ◽  
Line Segments ◽  
Compression Direction ◽  
Electron Backscatter ◽  
Grain Orientation Spread ◽  
Backscatter Diffraction

The main aim of the present work is to study the relation between microstructural features – such as local misorientations, grain orientation gradients and grain boundary structures – and thermomechanical treatment of hexagonal zirconium (Zr702α). Electron backscatter diffraction (EBSD) topological maps are used to analyze the aforementioned material parameters at the early stages of plastic deformation imposed by channel-die compression, as well as at a partial recrystallization state achieved by brief annealing. The evolution of local misorientations and orientation gradients is investigated using the so-called kernel average misorientation (KAM) and grain orientation spread (GOS) statistics implemented in the TSLOIMdata analysis software [TexSEM Laboratories (2004), Draper, UT, USA]. In the case of grain boundaries (GBs) a new method of analysis is presented. As an addition to the classical line segments method, where the grain boundary is represented by line segments that separate particular pairs of neighboring points, an approach that focuses on grain boundary areas is proposed. These areas are represented by sets of EBSD points, which are specially selected from a modified calculation procedure for the KAM. Different evolution mechanisms of intragranular boundaries, low-angle grain boundaries and high-angle grain boundaries are observed depending on the compression direction. The observed differences are consistent with the results obtained from KAM and GOS analysis. It is also concluded that the proposed method of grain boundary characterization seems to be promising, as it provides new and interesting analysis tools such as textures, absolute fractions and other EBSD statistics of the GB areas. This description may be more compatible with a real deformed microstructure, especially for grain boundaries with very small misorientation, which are indeed clustered areas of lattice defect accumulation.

Effect of Pile-Up on Nanoindentation Measurements of Polycrystalline Bulk Metals

2013 ◽  
Vol 853 ◽  
pp. 143-150 ◽  
Author(s):  
Reza A. Mirshams ◽  
Ashish K. Srivastava
Keyword(s):  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Surface Probe ◽  
Polycrystalline Metals ◽  
Pile Up ◽  
Electron Backscatter ◽  
Ebsd Technique ◽  
Backscatter Diffraction ◽  
Scanning Electron

This paper presents the results of an experimental investigation on the effects of orientation and grain size on nanoindentation measurements of hardness and modulus of elasticity for three polycrystalline metals: copper, nickel, and iron. Three geometrically different indenter tips were used, and the pile-ups were characterized with a surface probe instrument. The electron backscatter diffraction (EBSD) technique and a scanning electron microscope (SEM) were used to characterize grain orientation and microstructure. It was found that additional contact areas due to pile-ups have a significant effect on determination of mechanical properties by the nanoindenter.

Roping Phenomena in Aluminium Alloy 6016: A Microtextural Investigation

2010 ◽  
Vol 638-642 ◽  
pp. 396-400 ◽  
Author(s):  
Tricia A. Bennett ◽  
Jurij J. Sidor ◽  
Roumen H. Petrov ◽  
Leo Kestens
Keyword(s):  
Aluminium Alloys ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Spatial Distributions ◽  
Process Characterization ◽  
Electron Backscatter ◽  
The Difference ◽  
Backscatter Diffraction ◽  
Different Levels

Roping was investigated in two 6016 aluminium alloys that exhibit different levels of susceptibility to its occurrence. The level of roping is lower, as manifested by the less pronounced (roping) lines on the surface, in the GR material compared to the BR case. Through-process characterization of GR and BR materials by means of electron backscatter diffraction (EBSD) reveals similarities in the grain size, (grain) orientation texture and the spatial distribution of {100} <001> Cube grains up to, but not including the T4 state. Cube grains in the T4 state are spatially banded in the BR material but more uniformly distributed in the GR case. It was found that the thermo-mechanical treatments prior to the T4 state account for the difference in spatial distributions of Cube grains and hence, the different roping behaviours exhibited by these materials.

Grain Boundary Self-Diffusion in Nickel

2007 ◽  
Vol 263 ◽  
pp. 207-212 ◽  
Author(s):  
Vĕra Rothová ◽  
Jiří Buršík ◽  
Milan Svoboda ◽  
Jiří Čermák
Keyword(s):  
Grain Boundary ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Coincidence Site Lattice ◽  
Self Diffusion ◽  
Electron Backscatter ◽  
Cold Rolled ◽  
Backscatter Diffraction ◽  
Arrhenius Temperature ◽  
Diffusion Profiles

Grain boundary self-diffusion in both the cast and the cold-rolled Puratronic 4N5 nickel was studied in the temperature range from 600 °C to 1000 °C. The experiments were carried out with the samples pre-annealed at 1100 °C in comparison to the samples pre-annealed at intended individual diffusion temperatures. The relative grain orientation was analyzed on the same samples by means of electron backscatter diffraction (EBSD) and grain boundaries (GBs) were characterized in terms of the coincidence site lattice (CSL) model. Considering the non-linear Arrhenius temperature dependencies obtained for most specimens by using conventional method of profile evaluation in the B-type kinetics and the appearance of two high-diffusivity paths in diffusion profiles measured, a more suitable BB-type and AB-type diffusion models were applied for data evaluation.

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