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Sun, 26 Sep 2021 10:19:13 GMT
20210926T10:19:13Z

Problem of elastic anisotropy and stacking faults in stress analysis using multireflection grazingincidence Xray diffraction
http://hdl.handle.net/10985/9846
Problem of elastic anisotropy and stacking faults in stress analysis using multireflection grazingincidence Xray diffraction
MARCISZKO, Marianna; BACZMANSKI, Andrzej; MIROSŁAW, Wrobel; SEILER, Wilfrid; BRAHAM, Chedly; WRONSKI, Sebastian; WAWSZCZAK, Roman
Multireflection grazingincidence Xray diffraction (MGIXD) was used to determine the stress and strainfree lattice parameter in the surface layer of mechanically treated (polished and ground) tungsten and austenitic steel. It was shown that reliable diffraction stress analysis is possible only when an appropriate grain interaction model is applied to an anisotropic sample. Therefore, verification of the Xray stress factors (XSFs) was accomplished by measuring relative lattice strains during an in situ tensile test. The results obtained using the MGIXD and standard methods ( and geometries) show that the Reuss and freesurface grain interaction models agree with the experimental data. Moreover, a new interpretation of the MGIXD results was proposed and applied for the first time to measure the probability of stacking faults as a function of penetration depth for a polished and ground austenitic sample. The XSF models verified in the tensile test were used in the analysis of residual stress components.
Thu, 01 Jan 2015 00:00:00 GMT
http://hdl.handle.net/10985/9846
20150101T00:00:00Z
MARCISZKO, Marianna
BACZMANSKI, Andrzej
MIROSŁAW, Wrobel
SEILER, Wilfrid
BRAHAM, Chedly
WRONSKI, Sebastian
WAWSZCZAK, Roman
Multireflection grazingincidence Xray diffraction (MGIXD) was used to determine the stress and strainfree lattice parameter in the surface layer of mechanically treated (polished and ground) tungsten and austenitic steel. It was shown that reliable diffraction stress analysis is possible only when an appropriate grain interaction model is applied to an anisotropic sample. Therefore, verification of the Xray stress factors (XSFs) was accomplished by measuring relative lattice strains during an in situ tensile test. The results obtained using the MGIXD and standard methods ( and geometries) show that the Reuss and freesurface grain interaction models agree with the experimental data. Moreover, a new interpretation of the MGIXD results was proposed and applied for the first time to measure the probability of stacking faults as a function of penetration depth for a polished and ground austenitic sample. The XSF models verified in the tensile test were used in the analysis of residual stress components.

A multireflection and multiwavelength residual stress determination method using energy dispersive diffraction
http://hdl.handle.net/10985/14077
A multireflection and multiwavelength residual stress determination method using energy dispersive diffraction
MARCISZKO, Marianna; WAWSZCZAK, Roman; SIDHOM, Habib; BRAHAM, Chedly; WROBEL, Mirosław; WRONSKI, Sebastian; OPONOWICZ, Adrian; GENZEL, Christoph; KLAUS, Manuela; BACZMANSKI, Andrzej
The main focus of the presented work was the investigation of structure and residual stress gradients in the nearsurface region of materials studied by Xray diffraction. The multireflection method was used to measure depthdependent stress variation in nearsurface layers of a Ti sample (grade 2) subjected to different mechanical treatments. First, the multireflection grazing incidence diffraction method was applied on a classical diffractometer with Cu Kα radiation. The applicability of the method was then extended by using a white synchrotron beam during an energy dispersive (ED) diffraction experiment. An advantage of this method was the possibility of using not only more than one reflection but also different wavelengths of radiation. This approach was successfully applied to analysis of data obtained in the ED experiment. There was good agreement between the measurements performed using synchrotron radiation and those with Cu Kα radiation on the classical diffractometer. A great advantage of highenergy synchrotron radiation was the possibility to measure stresses as well as the a0 parameter and c0/α0 ratio for much larger depths in comparison with laboratory Xrays. © 2018 International Union of Crystallography.
Mon, 01 Jan 2018 00:00:00 GMT
http://hdl.handle.net/10985/14077
20180101T00:00:00Z
MARCISZKO, Marianna
WAWSZCZAK, Roman
SIDHOM, Habib
BRAHAM, Chedly
WROBEL, Mirosław
WRONSKI, Sebastian
OPONOWICZ, Adrian
GENZEL, Christoph
KLAUS, Manuela
BACZMANSKI, Andrzej
The main focus of the presented work was the investigation of structure and residual stress gradients in the nearsurface region of materials studied by Xray diffraction. The multireflection method was used to measure depthdependent stress variation in nearsurface layers of a Ti sample (grade 2) subjected to different mechanical treatments. First, the multireflection grazing incidence diffraction method was applied on a classical diffractometer with Cu Kα radiation. The applicability of the method was then extended by using a white synchrotron beam during an energy dispersive (ED) diffraction experiment. An advantage of this method was the possibility of using not only more than one reflection but also different wavelengths of radiation. This approach was successfully applied to analysis of data obtained in the ED experiment. There was good agreement between the measurements performed using synchrotron radiation and those with Cu Kα radiation on the classical diffractometer. A great advantage of highenergy synchrotron radiation was the possibility to measure stresses as well as the a0 parameter and c0/α0 ratio for much larger depths in comparison with laboratory Xrays. © 2018 International Union of Crystallography.

Multireflection grazingincidence Xray diffraction: A new approach to experimental data analysis
http://hdl.handle.net/10985/17932
Multireflection grazingincidence Xray diffraction: A new approach to experimental data analysis
MARCISZKOWIĄCKOWSKA, Marianna; OPONOWICZ, Adrian; BACZMANSKI, Andrzej; WRÓBEL, Mirosław X.; BRAHAM, Chedly; WAWSZCZAK, Roman
The multireflection grazingincidence Xray diffraction method is used to test surface stresses at depths of several micrometres in the case of metal samples. This work presents new ways of analysing experimental data obtained by this method for Ni samples exhibiting significant elastic anisotropy of crystals. Three different methods of determining biaxial stresses and lattice parameter were compared. In the first approach, the calculations were performed using the linear leastsquares method, and then two simplified procedures based on simple linear regression (weighted and nonweighted) were applied. It was found that all the tested methods give similar results, i.e. almost equal values of the determined stresses and lattice parameters and the uncertainties of their determination. The advantage of analyses based on simple linear regression is their simplicity and straightforward interpretation, enabling easy verification of the influence of the crystallographic texture and the presence of shear stresses, as well as graphical determination of the stressfree lattice parameter.
Tue, 01 Jan 2019 00:00:00 GMT
http://hdl.handle.net/10985/17932
20190101T00:00:00Z
MARCISZKOWIĄCKOWSKA, Marianna
OPONOWICZ, Adrian
BACZMANSKI, Andrzej
WRÓBEL, Mirosław X.
BRAHAM, Chedly
WAWSZCZAK, Roman
The multireflection grazingincidence Xray diffraction method is used to test surface stresses at depths of several micrometres in the case of metal samples. This work presents new ways of analysing experimental data obtained by this method for Ni samples exhibiting significant elastic anisotropy of crystals. Three different methods of determining biaxial stresses and lattice parameter were compared. In the first approach, the calculations were performed using the linear leastsquares method, and then two simplified procedures based on simple linear regression (weighted and nonweighted) were applied. It was found that all the tested methods give similar results, i.e. almost equal values of the determined stresses and lattice parameters and the uncertainties of their determination. The advantage of analyses based on simple linear regression is their simplicity and straightforward interpretation, enabling easy verification of the influence of the crystallographic texture and the presence of shear stresses, as well as graphical determination of the stressfree lattice parameter.