Compared Nitrogen Implantations of Various Alloyed Steels

1987 ◽  
Vol 93 ◽  
Author(s):  
N. Moncoffre ◽  
H. Jaffrezic ◽  
G. Marest ◽  
J. Tousset ◽  
F. C. Zawislak ◽  
...  
Keyword(s):  
Grazing Angle ◽  
Nuclear Reaction Analysis ◽  
X Ray Diffraction ◽  
M6ssbauer Spectroscopy ◽  
Surface Layers ◽  
Implantation Time ◽  
X Ray ◽  
Nitride Formation ◽  
Conversion Electron M6ssbauer Spectroscopy ◽  
The Matrix

ABSTRACTNitrogen implantations in pure iron and various stE-els are investigated using nuclear reaction analysis, Conversion Electron M6ssbauer Spectroscopy and Grazing angle X-ray Diffraction. The present work sums up all the significant results although it does not constitue a systematic study. It describes the influence of the chemical composition and the structure effect of the matrix as well as those of the implantation time. The N-martensite, ε-nitride and ε-carbonitride phases are principally identified. The fraction of iron bound with nitrogen is evaluated in the different steels. The strong influence of the small chromium amounts inside the matrix upon the nitride formation is underlined. A preferential orientation of these phases is shown. SIMS experiments are presented in particular to determine the carbon distribution in the first surface layers.

Nitride formation in iron after nitrogen implantation in a nickel top layer

1998 ◽  
Vol 13 (2) ◽  
pp. 440-445 ◽  
Author(s):  
D. K. Inia ◽  
F. D. Tichelaar ◽  
W. M. Arnoldbik ◽  
A. M. Vredenberg ◽  
D. O. Boerma
Keyword(s):  
Implantation Dose ◽  
Nuclear Reaction Analysis ◽  
X Ray Diffraction ◽  
Nitrogen Implantation ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Nitride Formation ◽  
Analysis Technique ◽  
Concentration Depth Profiles

Nitrogen was introduced in an iron layer underneath a top layer of nickel. This was done by ion implantation of N into the Ni layer at a temperature of 200 °C. During implantation and subsequent anneals at 250 and 300 °C, N diffuses from the Ni layer into the Fe layer because of a larger affinity of Fe for N than of Ni for N. The concentration depth profiles of N in the Ni/Fe bilayers, as recorded with the nuclear reaction analysis technique, show at the highest implantation dose a peak below the Ni/Fe interface. From structural analysis techniques (x-ray diffraction and cross-sectional transmission electron microscopy) it was observed that this peak is due to the presence of an ε–Fe3−xN layer below the Ni/Fe interface. It is thus shown that ε –nitride can be formed in Fe at such low temperatures in the absence of radiation damage.

Residual Stress in and Microstructure of Fe and Ti Surface Layers After 1 Mev N+ Implantation at High Dose

1989 ◽  
Vol 157 ◽  
Author(s):  
A.M. Vredenberg ◽  
F.W. Saris ◽  
N.M. v.d. Pers ◽  
P.F. Colijn ◽  
Th.H. de Keijser ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Stress Analysis ◽  
Peak Concentration ◽  
High Dose ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Volume Increase ◽  
X Ray ◽  
Nitride Formation

ABSTRACTThe effect of 1 MeV N+ irradiation on the microstructure of Fe and Ti specimens was investigated. The Fe and Ti specimens were implanted such that the N peak concentration (30 at.% in Fe, 45 at.% in Ti), was below the concentration of N in ε-Fe2N and δ-TiN, respectively. X-ray diffraction phase analysis showed that ε-Fe2N and δ-TiN had formed. X-ray diffraction stress analysis indicated that the residual stress in the Fe and Ti matrices was negligible after implantation. This suggests that the volume misfit due to nitride formation had been accommodated by plastic deformation. Indeed, surface profilometry of implanted Fe showed that a volume increase of the specimen had occurred which was compatible with the formation of unstrained nitride .

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Characteristics of Ni–Cr–Fe laser clad layers on EA4T steel

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744031
Author(s):  
Wenjing Chen ◽  
Hui Chen ◽  
Yongjing Wang ◽  
Congchen Li ◽  
Xiaoli Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Feeding Speed ◽  
Upper Bainite ◽  
Scanning Electron

The Ni–Cr–Fe metal powder was deposited on EA4T steel by laser cladding technology. The microstructure and chemical composition of the cladding layer were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bonding ability between the cladding layer and the matrix was measured. The results showed that the bonding between the cladding layer and the EA4T steel was metallurgical bonding. The microstructure of cladding layer was composed of planar crystals, columnar crystals and dendrite, which consisted of Cr2Ni3, [Formula: see text] phase, M[Formula: see text]C6 and Ni3B phases. When the powder feeding speed reached 4 g/min, the upper bainite occurred in the heat affected zone (HAZ). Moreover, the tensile strength of the joint increased, while the yield strength and the ductility decreased.

Detection of Compositional Fluctuations in High Temperature Exposed Waspaloy

2001 ◽  
Vol 699 ◽  
Author(s):  
Xiaodong Zou ◽  
Tariq Makram ◽  
Rosario A. Gerhardt
Keyword(s):  
Exposure Time ◽  
Structural Integrity ◽  
Thermal Exposure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gamma Prime ◽  
Distribution Shape ◽  
The Matrix ◽  
Quantitative Stereology ◽  
Nickel Base

AbstractWaspaloy is a nickel base super-alloy used in aircraft engines. When this alloy is placed in service, it is subjected to long term exposure at high temperatures, which can cause the reinforcing gamma prime precipitate population to fluctuate and thus affect its structural integrity. The population fluctuates as a result of coarsening, dissolution or re-precipitation. Samples exposed to 1200° F for times ranging from 0 to 12626 hours were characterized using impedance spectroscopy, microhardness measurements, x-ray diffraction and quantitative stereology. Two important parameters were derived from the impedance measurements: (1) the imaginary admittance peak magnitude (Ymax) and (2) the associated relaxation frequency (fmax). As the distribution, shape and size of the precipitates change with exposure time, these parameters were also found to vary. In addition to the changes in precipitate geometry, lattice constant changes detected by analyzing x-ray diffraction data suggest that there are compositional shifts in the matrix as well as the gamma prime precipitates. Furthermore, the preferred orientation of the precipitates can also be seen to change with exposure time. These changes in composition, size and shape as a function of thermal exposure time are accompanied by changes in the volume fractions of primary and secondary gamma prime particles present. Using effective medium models, it is possible to predict that the measured properties are related to the gamma prime population. The grain boundary carbides do not appear to play any role at the conditions presented.

Grazing-angle Incidence X-ray Diffraction by the Si1-α(x)-β(x)Geβ(x)Cβ(x)/Si Heterojunction where the Germanium and the Carbon Concentrations are Periodically Varying along the Flat Layer Surface

2002 ◽  
Vol 716 ◽  
Author(s):  
Hayk H. Bezirganyan ◽  
Siranush E. Bezirganyan ◽  
Hakob P. Bezirganyan ◽  
Petros H. Bezirganyan
Keyword(s):  
Strain Field ◽  
Grazing Angle ◽  
Layer Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermediate Transformation ◽  
Long Period ◽  
Theoretical Paper ◽  
Carbon Concentrations ◽  
Coherent Part

AbstractPresented theoretical paper concerns the investigation of SiGeC/Si heterojunction by the Grazing-angle Incidence X-ray Diffraction (GIXD) method. We consider a possibility in principal of the GIXD by the specific long-range harmonic variations of the germanium and carbon compositions in the thin SiGeC layer. Evaluation of the theoretically calculated coherent part of x-radiation scattered by the SiGeC layer points the way to the experimental direct investigations of the long-period structured intermediate transformation states of SiGeC layer that emerge owing to inhomogeneity of the strain field along the heterojunction surface.

scholarly journals Влияние режима получения образцов и термообработки на локальную структуру халькогенидного полупроводника Ge-=SUB=-2-=/SUB=-Sb-=SUB=-2-=/SUB=-Te-=SUB=-5-=/SUB=-

2022 ◽  
Vol 56 (3) ◽  
pp. 291
Author(s):  
С.Н. Гарибова ◽  
А.И. Исаев ◽  
С.И. Мехтиева ◽  
С.У. Атаева ◽  
Р.И. Алекперов
Keyword(s):  
Heat Treatment ◽  
Thermal Processing ◽  
Thermal Evaporation ◽  
Amorphous State ◽  
Hexagonal Structure ◽  
Structural Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Close Range

Specifics of "amorphous state - crystal" phase transitions in dependence on the samples obtaining method and thermal processing, as well as changes in the structure and close range order in the arrangement of the atoms of Ge20Sb20.5Te51 chalcogenide semiconductors have been studied by the x-ray diffraction and Raman spectroscopy. It has been shown that Ge20Sb20.5Te51 films obtained by thermal evaporation on an unheated substrate are amorphous; after heat treatment at 220 and 400 °C, transform into a crystalline phase with a cubic and hexagonal structure. The chemical bonds and the main structural elements that form the matrix of the investigated objects, as well as the changes that occur in them during heat treatment, have been determined.

scholarly journals Thermal History of Matrix Forsterite Grains from Murchison Based on High-resolution Tomography

2021 ◽  
Vol 922 (2) ◽  
pp. 256
Author(s):  
Giulia Perotti ◽  
Henning O. Sørensen ◽  
Henning Haack ◽  
Anja C. Andersen ◽  
Dario Ferreira Sanchez ◽  
...  
Keyword(s):  
High Resolution ◽  
Electron Density ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Maps ◽  
Thermally Processed ◽  
The Matrix ◽  
History Of ◽  
Chondrule Formation

Abstract Protoplanetary disks are dust- and gas-rich structures surrounding protostars. Depending on the distance from the protostar, this dust is thermally processed to different degrees and accreted to form bodies of varying chemical compositions. The primordial accretion processes occurring in the early protoplanetary disk such as chondrule formation and metal segregation are not well understood. One way to constrain them is to study the morphology and composition of forsteritic grains from the matrix of carbonaceous chondrites. Here, we present high-resolution ptychographic X-ray nanotomography and multimodal chemical microtomography (X-ray diffraction and X-ray fluorescence) to reveal the early history of forsteritic grains extracted from the matrix of the Murchison CM2.5 chondrite. The 3D electron density maps revealed, at unprecedented resolution (64 nm), spherical inclusions containing Fe–Ni, very little silica-rich glass and void caps (i.e., volumes where the electron density is consistent with conditions close to vacuum) trapped in forsterite. The presence of the voids along with the overall composition, petrological textures, and shrinkage calculations is consistent with the grains experiencing one or more heating events with peak temperatures close to the melting point of forsterite (∼2100 K), and subsequently cooled and contracted, in agreement with chondrule-forming conditions.

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