High temperature micromechanical behavior of Ti2AlN particle reinforced TiAl based composites investigated by in-situ high-energy X-ray diffraction

The combination of high temperature (1050°C -1150°C) testing and in situ high energy X-Ray diffraction measurements using synchrotron Three Crystal Diffractometry may give various insights into the mechanical behaviour of superalloys: measurement of the lattice mismatch, order within the ' phase, elastic constants, and dynamic response to changes in the experimental conditions. Several examples are given on the rafted AM1 superalloy, resulting from experiments at the ID15A (ESRF) and BW5 (DESY) high energy beamlines.

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High-energy synchrotron radiation X-ray diffraction measurements during in situ aging of a NiTi-15 at. % Hf high temperature shape memory alloy

Materialia ◽

10.1016/j.mtla.2019.100220 ◽

2019 ◽

Vol 5 ◽

pp. 100220 ◽

Cited By ~ 2

Author(s):

Matthew Carl ◽

Jesse Smith ◽

Robert W. Wheeler ◽

Yang Ren ◽

Brian Van Doren ◽

...

Keyword(s):

High Temperature ◽

Synchrotron Radiation ◽

Shape Memory Alloy ◽

Shape Memory ◽

High Energy ◽

X Ray Diffraction ◽

X Ray

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Time-resolved in situ powder X-ray diffraction reveals the mechanisms of molten salt synthesis

Chemical Communications ◽

10.1039/c6cc08133a ◽

2016 ◽

Vol 52 (96) ◽

pp. 13865-13868 ◽

Cited By ~ 10

Author(s):

Saul J. Moorhouse ◽

Yue Wu ◽

Hannah C. Buckley ◽

Dermot O'Hare

Keyword(s):

High Temperature ◽

Molten Salt ◽

Powder Diffraction ◽

High Energy ◽

Chemical Processes ◽

Molten Salt Synthesis ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray

We report the first use of high-energy monochromatic in situ X-ray powder diffraction to gain unprecedented insights into the chemical processes occurring during high temperature, lab-scale metal oxide syntheses.

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Stress-controlled decomposition routes in cubic AlCrN films assessed by in-situ high-temperature high-energy grazing incidence transmission X-ray diffraction

Scientific Reports ◽

10.1038/s41598-019-54307-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

M. Meindlhumer ◽

S. Klima ◽

N. Jäger ◽

A. Stark ◽

H. Hruby ◽

...

Keyword(s):

High Temperature ◽

Transition Metal ◽

Stress Level ◽

Grazing Incidence ◽

High Energy ◽

Metal Nitrides ◽

Transition Metal Nitrides ◽

X Ray Diffraction ◽

X Ray

AbstractThe dependence of decomposition routes on intrinsic microstructure and stress in nanocrystalline transition metal nitrides is not yet fully understood. In this contribution, three Al0.7Cr0.3N thin films with residual stress magnitudes of −3510, −4660 and −5930 MPa in the as-deposited state were in-situ characterized in the range of 25–1100 °C using in-situ synchrotron high-temperature high-energy grazing-incidence-transmission X-ray diffraction and temperature evolutions of phases, coefficients of thermal expansion, structural defects, texture as well as residual, thermal and intrinsic stresses were evaluated. The multi-parameter experimental data indicate a complex intrinsic stress and phase changes governed by a microstructure recovery and phase transformations taking place above the deposition temperature. Though the decomposition temperatures of metastable cubic Al0.7Cr0.3N phase in the range of 698–914 °C are inversely proportional to the magnitudes of deposition temperatures, the decomposition process itself starts at the same stress level of ~−4300 MPa in all three films. This phenomenon indicates that the particular compressive stress level functions as an energy threshold at which the diffusion driven formation of hexagonal Al(Cr)N phase is initiated, provided sufficient temperature is applied. In summary, the unique synchrotron experimental setup indicated that residual stresses play a decisive role in the decomposition routes of nanocrystalline transition metal nitrides.

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Thermal expansion of ellinaite (β-CaCr2O4): an in-situ high temperature X-ray diffraction study

Physics and Chemistry of Minerals ◽

10.1007/s00269-020-01126-2 ◽

2021 ◽

Vol 48 (1) ◽

Author(s):

Weihong Xue ◽

Kuan Zhai ◽

Shuangmeng Zhai

Keyword(s):

Thermal Expansion ◽

High Temperature ◽

Diffraction Study ◽

X Ray Diffraction ◽

X Ray

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In-Situ High-Energy X-ray Diffraction Study of Austenite Decomposition During Rapid Cooling and Isothermal Holding in Two HSLA Steels

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06192-x ◽

2021 ◽

Vol 52 (5) ◽

pp. 1812-1825

Author(s):

Sen Lin ◽

Ulrika Borggren ◽

Andreas Stark ◽

Annika Borgenstam ◽

Wangzhong Mu ◽

...

Keyword(s):

Isothermal Holding ◽

Weight Percent ◽

High Energy ◽

Decomposition Kinetics ◽

Bainitic Transformation ◽

Austenite Decomposition ◽

X Ray Diffraction ◽

Rapid Cooling ◽

X Ray

AbstractIn-situ high-energy X-ray diffraction experiments with high temporal resolution during rapid cooling (280 °C s−1) and isothermal heat treatments (at 450 °C, 500 °C, and 550 °C for 30 minutes) were performed to study austenite decomposition in two commercial high-strength low-alloy steels. The rapid phase transformations occurring in these types of steels are investigated for the first time in-situ, aiding a detailed analysis of the austenite decomposition kinetics. For the low hardenability steel with main composition Fe-0.08C-1.7Mn-0.403Si-0.303Cr in weight percent, austenite decomposition to polygonal ferrite and bainite occurs already during the initial cooling. However, for the high hardenability steel with main composition Fe-0.08C-1.79Mn-0.182Si-0.757Cr-0.094Mo in weight percent, the austenite decomposition kinetics is retarded, chiefly by the Mo addition, and therefore mainly bainitic transformation occurs during isothermal holding; the bainitic transformation rate at the isothermal holding is clearly enhanced by lowered temperature from 550 °C to 500 °C and 450 °C. During prolonged isothermal holding, carbide formation leads to decreased austenite carbon content and promotes continued bainitic ferrite formation. Moreover, at prolonged isothermal holding at higher temperatures some degenerate pearlite form.

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