scholarly journals The Low-Angle Boundaries Misorientation and Lattice Parameter Changes in the Root of Single-Crystalline CMSX-4 Superalloy Blades

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5194
Author(s):  
Robert Paszkowski ◽  
Włodzimierz Bogdanowicz ◽  
Dariusz Szeliga
Keyword(s):  
Electron Microscopy ◽  
Turbine Blades ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
Internal Stresses ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
The Relationship ◽  
Scanning Electron

The relationship between the angles of misorientation of macroscopic low-angle boundaries (LABs) and changes in the lattice parameter of the γ′-phase around the LABs in the root of single-crystalline (SX) turbine blades made of CMSX-4 superalloy were studied. The blades with an axial orientation of the [001] type were solidified using an industrial Bridgman furnace with a 3 mm/min withdrawal rate. X-ray diffraction topography, the EFG Ω-scan X-ray diffraction method, scanning electron microscopy, and Laue diffraction were used to study the thin lamellar samples with a thickness of 0.5 mm and orientation of the surface perpendicular to the [001] direction. It is found that in the areas with a width of a few millimetres around LABs, decreases in the lattice parameter of the γ′-phase occur. These lattice parameter changes are related to the internal stresses of the γ′-phase caused by local changes in the concentration of alloying elements and/or to the dendrite bending near the LABs. X-ray topography used on two surfaces of thin lamellar samples coupled with the lattice parameter measurements of the γ′-phase near the LAB allows separating the misorientation component of LAB diffraction contrast from the component and visualising the internal stresses of the γ′-phase.

SIZE-INDUCED EFFECTS IN NANOSTRUCTURED NiFe2O4

2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Hydrothermal Process ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

scholarly journals The Influence of the Cooling Bores on the Dendritic Structure and Crystal Orientation in Single-Crystalline Cored CMSX-4 Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3966
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz
Keyword(s):  
Crystal Orientation ◽  
Turbine Blades ◽  
Dendritic Structure ◽  
X Ray Diffraction ◽  
Vertical Temperature ◽  
Single Crystalline ◽  
X Ray ◽  
Vertical Bridgman ◽  
The Relationship

Single-crystalline cored CMSX-4 blades obtained at a withdrawal rate of 3 mm/min by the vertical Bridgman method were analyzed. The dendritic structure and crystal orientation near the cooling bores of the blades were studied through Scanning Electron Microscopy, the X-ray diffraction measurements of α and β angular components of the primary crystal orientation, and the γ angular component of the secondary crystal orientation. Additionally, the primary arm spacing (PAS) was studied in areas near and far from the cooling bores. It was found that in the area approximately 3–4 mm wide around the cooling bores, changes occurred in the α, β, and γ angles, as well as in the PAS. The PAS determined for the transverse section of the root and the linear primary arm spacing (LPAS) determined for the longitudinal sections, as well as their relationship, have been defined for the areas located near the cooling bores and those at a distance from them. The vertical temperature gradient of 29.5 K/cm was estimated in the root areas located near the cooling bores based on the PAS values. The value of this gradient was significantly higher compared to the growth chamber operating gradient of 16 K/cm. The two-scale analysis applied in this study allowed for the determination of the relationship between the process of dendrite array creation proceeding on a millimeter scale, which is associated with the local changes in crystal orientation near the cooling bores, and that which proceeds on a scale of tens of millimeters, associated with the changes in crystal orientation in the whole blade cast.

scholarly journals The Influence of the Cooling Bores on Crystal Orientation and Lattice Parameter in Single-Crystalline Cored Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3842
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Jan Sieniawski
Keyword(s):  
Solidification Front ◽  
Crystal Orientation ◽  
Turbine Blades ◽  
Lattice Parameter ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
Vertical Bridgman ◽  
Α Angle

The areas located near the cooling bores of single-crystalline cored turbine blades made of nickel-based CMSX-4 superalloy were studied. The blades were solidified by the vertical Bridgman technique in the industrial ALD furnace. Longitudinal sections of the blades were studied by Scanning Electron Microscopy, X-ray diffraction topography, X-ray diffraction measurements of the γ′-phase lattice parameter a, and the α angle of the primary crystal orientation. The local changes in α were analyzed in relation to the changes of the dendrite’s growth direction near the cooling bores. It was found that in the area approximately 3 ÷ 4 mm wide around the cooling bores, changes of α and a, both in the blade root and in the airfoil occurred. The local temperature distribution near the cooling bores formed a curved macroscopic solidification front, which caused changes in the chemical composition and, consequently, changes in the a value in a range of 0.002 Å to 0.014 Å. The mechanism of alloying elements segregation by tips of the dendrites on the bent solidification front was proposed. The multi-scale analysis that allows determining a relation between processes proceed both on a millimeter-scale and a micrometric and nanometric scale, was applied in the studies.

Effect of Heat Treatment on the Microstructure and Creep Behavior of Mg-Sn-Ca Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 69-72 ◽  
Author(s):  
Tarek Abu Leil ◽  
Yuan Ding Huang ◽  
Hajo Dieringa ◽  
Norbert Hort ◽  
Karl Ulrich Kainer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Creep Behaviour ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Industrial Use ◽  
The Relationship ◽  
Thermal Stable ◽  
Scanning Electron

The development of new Mg-Sn based alloys that have shown improved corrosion resistance needs further investigations to develop standard alloys for industrial use. In the present study, the influence of heat treatment was investigated by examining the creep resistance of Mg-Sn and Mg-Sn-Ca alloys at 85 MPa under 135 °C identify the best conditions to improve the mechanical properties of such alloys. Additionally, the changes in microstructure of these alloys were studied and analysed by light microscopy, X-ray diffraction and scanning electron microscopy. It was found that the heat treatments can affect the microstructure of the binary alloy while no apparent change in the microstructure was found in the Mg-Sn-Ca alloys, indicating that the second phase CaMgSn is thermal stable in this alloy. Based on the obtained results, the relationship between the microstructure and creep behaviour are discussed.

scholarly journals Recrystallization of Single-Crystalline VO2 Microtube Arrays on V2O5 Substrate

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 66
Author(s):  
Shuxiang Ma ◽  
Chunwang Zhao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cooling Rate ◽  
Thermal Oxidation ◽  
Peak Temperature ◽  
X Ray Diffraction ◽  
Resistive Heating ◽  
Single Crystalline ◽  
X Ray ◽  
Scanning Electron

Single-crystalline VO2 microtube arrays on V2O5 substrate were fabricated through a thermal oxidation route based on resistive heating V foil in air. Four sheets of as-fabricated single-crystalline VO2 microtube arrays on V2O5 substrate were then, respectively, heated to approximately 855 °C and 1660 °C to melt V2O5 or VO2. Thereafter, the melted V2O5 or VO2 was cooled rapidly or slowly to recrystallize the liquid V2O5 or VO2. The morphologies and phases of the recrystallization products were characterized by scanning electron microscopy and X-ray diffraction. This study proposes that the peak temperature of heating and the cooling rate are responsible for the recrystallization products of single-crystalline VO2 microtube arrays on V2O5 substrate.

Novel Process for Synthesizing Nano-Ceramics Powder: Mechanical & Thermal Activation Processing

2007 ◽  
Vol 280-283 ◽  
pp. 581-586 ◽  
Author(s):  
Xiao Long Cui ◽  
Li Shan Cui
Keyword(s):  
Electron Microscopy ◽  
Mechanical Activation ◽  
Thermal Activation ◽  
Processing Time ◽  
Lattice Parameter ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel process for synthesizing nano-ceramics powders, named Mechanical & Thermal Activation Processing, is discussed in the present paper. Dissimilar with the tradition processing of mechanical activation or mechanochemistry, the processing is based on thermal activation in liquid phase (molten salt) after mechanical activation. The synthesizing of nanometer sized TiC particles by the method was investigated. The end product has been analyzed by X-ray diffraction (XRD),transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersion X-ray (EDX). The results show that nano-meter sized particles were formed, and the lattice parameter of TiC is close to the value of non-oxygen TiC. Compared with usually methods, the whole processing time needed is shortened; moreover, the synthesis temperature could be reduced 500°C. The mechanism for mechanical & yhermal activation is discussed.

Soft-Template Synthesis of Single-Crystalline CdS Dendrites

2006 ◽  
Vol 6 (1) ◽  
pp. 162-167 ◽  
Author(s):  
Haixia Niu ◽  
Qing Yang ◽  
Kaibin Tang ◽  
Yi Xie ◽  
Yongchun Zhu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Soft Template ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

The single-crystalline CdS dendrites have been fabricated from the reaction of CdCl2 and thiourea at 180 °C, in which glycine was employed as a soft template. The obtained products were explored by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected area electronic diffraction. The optical properties of CdS dendrites have been investigated by ultraviolet and visible light (UV-vis) and photoluminescence techniques. The investigations indicated that the dendrites were grown due to the anisotropic properties enhanced by the use of Glycine in the route.

THE FORMATION AND EVOLUTION OF SINGLE-CRYSTALLINE SnO2 NANOBELTS

2011 ◽  
Vol 25 (19) ◽  
pp. 1643-1650
Author(s):  
JUN-HONG DUAN ◽  
CHAO YAN ◽  
XING-DAO HE ◽  
YI-QING GAO ◽  
PEI-QIN SHI ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Single Crystalline ◽  
Reaction Method ◽  
X Ray ◽  
Transmission Electron ◽  
Formation And Evolution ◽  
Sno2 Nanobelts ◽  
Scanning Electron

Single-crystalline SnO 2 zigzag nanobelts and straight nanobelts with triangular tip were synthesized by a simple Tin–water reaction method. The product was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman scattering and micro-photoluminescence spectroscopy to obtain the structural and optical information. Why zigzag nanobelts and straight nanobelts can be formed respectively under the same experimental conditions? On the basis of TEM characterization and thermodynamic analysis, the formation mechanism of zigzag nanobelts and straight nanobelts were proposed respectively.

Effect of Silk Reeling Velocity on the Aggregation Structure of Raw Silk

2011 ◽  
Vol 175-176 ◽  
pp. 496-499
Author(s):  
Li Na Li ◽  
Shi Qi Bai ◽  
Ya Qin Fu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Sonic Velocity ◽  
X Ray Diffraction ◽  
Orientation Degree ◽  
X Ray ◽  
Aggregation Structure ◽  
The Relationship ◽  
Scanning Electron

The aggregation structure of raw silk which influences the mechanical properties of raw silk directly is not only determined by the properties of cocoon but also affected by silk reeling velocity. In this study, the relationship between aggregation structure of raw silk and silk reeling velocity was studied by means of sonic velocity method, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The study showed that orientation degree, crystallinity and mechanical properties of raw silk were remarkably influenced by silk reeling velocity, and the mechanical properties of raw silk would be improved through the reasonable silk reeling velocity.

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