scholarly journals In Situ Analysis of the Phase Transformation Kinetics in the β-Water-Quenched Ti-5Al-5Mo-5V-3Cr-1Zr Alloy during Ageing after Fast Heating

2020 ◽  
Vol 4 (1) ◽  
pp. 12
Author(s):  
Rafael Paiotti Marcondes Guimarães ◽  
Bruna Callegari ◽  
Fernando Warchomicka ◽  
Katherine Aristizabal ◽  
Flavio Soldera ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Energy ◽  
Transformation Kinetics ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
X Ray ◽  
Β Phase ◽  
Phase Transformation Kinetics ◽  
Structural Applications

Thermal treatments are the main route to achieve improvements in mechanical properties of β-metastable titanium alloys developed for structural applications in automotive and aerospace industries. Therefore, it is of vital importance to determine phase transformation kinetics and mechanisms of nucleation and precipitation during heat treatment of these alloys. In this context, the present paper focuses on the assessment of solid-state transformations in a β-water-quenched Ti-5Al-5Mo-5V-3Cr-1Zr alloy during the early stages of ageing treatment at 500 °C. In situ tracking of transformations was performed using high-energy synchrotron X-ray diffraction. The transformation sequence β + ω → α + α”iso + β is proposed to take place during this stage. Results show that isothermal α” phase precipitates from ω and from spinodal decomposition domains of the β phase, whereas α nucleates from ω, β and also from α” with different morphologies. Isothermal α” is considered to be the regulator of transformation kinetics. Hardness measurements confirm the presence of ω, although this phase was not detected by X-ray diffraction during the in situ treatment.

scholarly journals In Situ Stress Tensor Determination during Phase Transformation of a Metal Matrix Composite by High-Energy X-ray Diffraction

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1415 ◽  
Author(s):  
Guillaume Geandier ◽  
Lilian Vautrot ◽  
Benoît Denand ◽  
Sabine Denis
Keyword(s):  
Phase Transformation ◽  
Stress Tensor ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
High Energy ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray

In situ high-energy X-ray diffraction using a synchrotron source performed on a steel metal matrix composite reinforced by TiC allows the evolutions of internal stresses during cooling to be followed thanks to the development of a new original experimental device (a transportable radiation furnace with controlled rotation of the specimen). Using the device on a high-energy beamline during in situ thermal treatment, we were able to extract the evolution of the stress tensor components in all phases: austenite, TiC, and even during the martensitic phase transformation of the matrix.

2.45 GHz Microwave Sintering of Silicon Nitride

2008 ◽  
Vol 403 ◽  
pp. 27-30
Author(s):  
S. Chockalingam ◽  
J.P. Kelly ◽  
V.R.W. Amarakoon ◽  
James R. Varner
Keyword(s):  
Phase Transformation ◽  
Oxidation Behavior ◽  
Microwave Sintering ◽  
Sintered Sample ◽  
Microstructure Development ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Structurally Stable

Microwave sintered Si3N4-MgO system that contains 2, 4 and 10 wt% of ZrO2 as secondary particulates were investigated with respect to phase transformation and microstructure development. The experimental results of microwave sintered samples were compared with conventional methods. Complete α to β phase transformation was observed in the case of microwave sintered samples due to the volumetric nature of microwave heating. High temperature X-ray diffraction (HTXRD) analysis was performed to study in-situ the oxidation behavior of Si3N4 specimens. Si3N4 specimens with 10 wt % ZrO2 were exposed to air at temperature between 25°C and 900°C for up to 24 hours. Microwave sintered sample were structurally stable in air 25°C and 900°C for up to 24 hours of testing.

In Situ High Energy X-Ray Diffraction for Investigating the Phase Transformation in Hot Rolled TRIP-Aided Steels

2014 ◽  
Vol 16 (8) ◽  
pp. 1044-1051 ◽  
Author(s):  
Piyada Suwanpinij ◽  
Andreas Stark ◽  
Xiaoxiao Li ◽  
Frank Römer ◽  
Klaus Herrmann ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hot Rolled

scholarly journals In situ synchrotron X-ray diffraction line-profile analysis of additively manufactured Ti−6Al−4V alloy under tensile deformation

2020 ◽  
Vol 321 ◽  
pp. 03026
Author(s):  
K. Yamanaka ◽  
A. Kuroda ◽  
M. Ito ◽  
M. Mori ◽  
T. Shobu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Line Profile ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
High Energy ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase

In this study, the tensile deformation behavior of an electron beam melted Ti−6Al−4V alloy was examined by in situ X-ray diffraction (XRD) line-profile analysis. The as-built Ti−6Al−4V alloy specimen showed a fine acicular microstructure that was produced through the decomposition of the α′-martensite during the post-melt exposure to high temperatures. Using high-energy synchrotron radiation, XRD line-profile analysis was successfully applied for examining the evolution of dislocation structures not only in the α-matrix but also in the nanosized, low-fraction β-phase precipitates located at the interfaces between the α-laths. The results indicated that the dislocation density was initially higher in the β-phase and an increased dislocation density with increasing applied tensile strain was quantitatively captured in each constitutive phase. It can be thus concluded that the EBM Ti−6Al−4V alloy undergoes a cooperative plastic deformation between the constituent phases in the duplex microstructure. These results also suggested that XRD line-profile analysis combined with highenergy synchrotron XRD measurements can be utilized as a powerful tool for characterizing duplex microstructures in titanium alloys.

In Situ Structural Evolution of Steel-Based MMC by High Energy X-Ray Diffraction and Comparison with Micromechanical Approach

2013 ◽  
Vol 768-769 ◽  
pp. 313-320 ◽  
Author(s):  
Guillaume Geandier ◽  
Moukrane Dehmas ◽  
Mickael Mourot ◽  
Elisabeth Aeby-Gautier ◽  
Sabine Denis ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Coefficient Of Thermal Expansion ◽  
Hydrostatic Stress ◽  
Structural Evolution ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
The Matrix

In situ high energy X-ray diffraction synchrotron was used to provide direct analysis of the transformation sequences in steel-based matrix composite (MMC) reinforced with TiC particles. Evolution of the phase fractions of the matrix and TiC particles as well as the mean cell parameters of each phase were determined by Rietveld refinement from high energy X-ray diffraction (ID15B, ESRF, Grenoble, France). In addition, some peaks were further analysed in order to obtain the X-ray strain during the cooling step. Non-linear strain evolutions of each phase are evidenced, which are either associated with differences in the coefficient of thermal expansion (CTE) between matrix and TiC particle or to the occurrence of phase transformation. Micromechanical calculations were performed through the finite element method to estimate the stress state in each phase and outline the effects of differences in CTE and of volume change associated with the matrix phase transformation. The calculated results led to a final compressive hydrostatic stress in the TiC reinforcement and tensile hydrostatic stress in the matrix area around the TiC particles. Besides, the tendencies measured from in situ synchrotron diffraction (mean cell parameters) matched with the numerical estimates.

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