Incremental ECAP as a method to produce ultrafine grained aluminium plates

In this work, we propose a new approach to producing ultrafine grained plates using a modified ECAP method, namely incremental ECAP. Unlike conventional ECAP, incremental ECAP works step by step whereby deformation and feeding are performed with two different tools acting asynchronously. Incremental processing reduces forces and allows to process relatively large billets. The major advantage of this technique is that the specimens are in the form of plates with a rectangular shape, which makes them suitable for further processing, e.g. via deep drawing. This paper reports a study on microstructure development, mechanical properties and their anisotropy in aluminium plates processed by means of incremental ECAP. Eight passes applied (with the accumulated strain of 9.2) with the rotation about the Z axis brought about the reduction in the grain size down to 600 nm with the 80% fraction of high angle grain boundaries and a very homogenous equiaxial microstructure. This, in turn, resulted in a significant increase in mechanical strength with the ultimate tensile strength reaching 200 MPa and, more importantly, very low anisotropy with respect to the rolling direction

Bridgman-grown (Cd,Mn)Te and (Cd,Mn)(Te,Se): A comparison of suitability for X and gamma detectors

This study explores the suitability of semi-insulating compounds, specifically (Cd,Mn)Te and (Cd,Mn)(Te,Se), as materials for room temperature X-ray and gamma-ray detectors. These compounds were grown using the Bridgman method, known for its efficient growth rate. The investigation aims to compare their crystal structure, mechanical properties, optical characteristics, and radiation detection capabilities. The addition of selenium to (Cd,Mn)Te increased the compound's hardness. However, (Cd,Mn)(Te,Se) exhibited one order of magnitude higher etch pit density compared to (Cd,Mn)Te. Photoluminescence analysis at low temperatures revealed the presence of defect states in both materials, characterized by shallow and deep donor-acceptor pair transitions (DAP). Annealing in cadmium vapors effectively eliminated DAP luminescence in (Cd,Mn)Te but not in (Cd,Mn)(Te,Se). Spectroscopic performance assessments indicated that the (Cd,Mn)Te detector outperformed the (Cd,Mn)(Te,Se) detector in responding to a Co-57 source. The reduced performance in the latter case may be attributed to either the presence of a deep trap related to deep DAP luminescence, minimally affected by annealing, or the dominant presence of block-like structures in the samples, as indicated by X-ray diffraction measurements. The block-like structures in (Cd,Mn)(Te,Se) showed ten times larger misorientation angles compared to the (Cd,Mn)Te crystals. (Cd,Mn)Te crystal revealed excellent single crystal properties, demonstrated by narrower omega scan widths. The study also highlights the influence of grain boundaries and twins on crystal structure quality. In our opinion, Bridgman-grown (Cd,Mn)Te shows greater promise as a material for X-ray and gamma-ray detectors compared to (Cd,Mn)(Te,Se).Comment: 33 pages, 11 figure

Ultrafine grained plates of Al-Mg-Si alloy obtained by Incremental Equal Channel Angular Pressing : microstructure and mechanical properties

In this study, an Al-Mg-Si alloy was processed using via Incremental Equal Channel Angular Pressing (I-ECAP) in order to obtain homogenous, ultrafine grained plates with low anisotropy of the mechanical properties. This was the first attempt to process an Al-Mg-Si alloy using this technique. Samples in the form of 3 mm-thick square plates were subjected to I-ECAP with the 90˚ rotation around the axis normal to the surface of the plate between passes. Samples were investigated first in their initial state, then after a single pass of I-ECAP and finally after four such passes. Analyses of the microstructure and mechanical properties demonstrated that the I-ECAP method can be successfully applied in Al-Mg-Si alloys. The average grain size decreased from 15 - 19 µm in the initial state to below 1 µm after four I-ECAP passes. The fraction of high angle grain boundaries in the sample subjected to four I-ECAP passes lay within 53-57 % depending on the examined plane. The mechanism of grain refinement in Al-Mg-Si alloy was found to be distinctly different from that in pure aluminium with the grain rotation being more prominent than the grain subdivision, which was attributed to lower stacking fault energy and the reduced mobility of dislocations in the alloy. The ultimate tensile strength increased more than twice, whereas the yield strength - more than threefold. Additionally, the plates processed by I-ECAP exhibited low anisotropy of mechanical properties (in plane and across the thickness) in comparison to other SPD processing methods, which makes them attractive for further processing and applications

Strengthening mechanisms in ultrafine grained Al-Mg-Si alloy processed by hydrostatic extrusion – Influence of ageing temperature

Microstructure of hydrostatically extruded Al-Mg-Si alloy was studied by the combination of electron backscattered diffraction and transmission electron microscopy. Three different grain types which feature various defects arrangements were detected. Post deformation ageing at two temperatures caused different precipitation phenomena which were strongly dependent on type of grain boundaries in the considered grain types. Thus, a combination of plastic deformation and ageing resulted in a material with complex microstructure. Based on transmission electron microscopy observations, contributions of different strengthening mechanisms were estimated and compared to experimental results. A good agreement between obtained data points confirmed that depending on grain type, different strengthening mechanisms are operative and the overall strength is a sum of hardening given by each of them. Ageing of ultrafine grain structure results in efficient precipitation strengthening. On the other hand ageing causes annihilation of low and high angle grains boundaries in which leads to softening of investigated material. This effect cannot be compensated by precipitation hardening

Microstructure and phase investigation of FeCrAl-Y2O3 ODS steels with different Ti and V contents

<p><strong><span>Description of data:</span></strong><span> The data set consists of seven main folders. The data is divided into folders based on the technique used to obtain the data. </span></p> <p><strong><span><span>      1.<span>      </span></span></span></strong><strong><span>XRD</span></strong><span> </span></p> <p><span>The XRD folder consists of two subfolders: </span></p> <p><span><span>·<span>        </span></span></span><strong><span>XRD of powder</span></strong><span>: raw data from diffractometer, which were used to create Fig. 3.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>XRD of bulk samples</span></strong><span>: raw data from diffractometer, which were used to prepare Fig. 10.</span></p> <p><strong><span><span>      2.<span>      </span></span></span></strong><strong><span>SEM</span></strong></p> <p><span>The SEM folder consists of six subfolders:</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of powder:</span></strong><span> SEM images, which were used to create Fig. 1 showing powder morphology.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>EDS of powder:</span></strong><span> SEM images and EDS spectra (<em>p11.tif</em>, <em>p13.tif</em>, <em>p30.tif</em>, <em>p32.tif</em>), which were used to create Fig. 2, show the chemical homogeneity of the powder.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of bulk samples:</span></strong><span> SEM images of bulk samples that were used to create Fig. 4.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>EDS of bulk samples:</span></strong><span> it consists of two SEM images of the region of interest (i.e., ODS-1-Ti.tif and ODS-2-TiV) and two .docx files (i.e., <em>ODS-1-Ti.docx</em> and <em>ODS-2-TiV.docx</em>) with maps of distribution of chemical elements selected for the analysis. These data were used to create Fig. 5. </span></p> <p><span><span>·<span>        </span></span></span><strong><span>EBSD of bulk samples:</span></strong><span> This subfolder consists of several files. <em>ODS-1-Ti_EBSD_grain_leg_info.txt</em> and <em>ODS-2-TiV_EBSD_grain_leg_info.txt</em> files<em> </em>consist of data from the EBSD software, which enable us to create a histogram of grain size in Fig. 9c. <em>ODS-1-Ti_EBSD_info.txt</em>, <em>ODS-1-Ti_EBSD_leg.bmp,</em> and <em>ODS-2-TiV_EBSD_info.txt, ODS-2-TiV_EBSD_leg.bmp</em> files contain information about the acquisition parameters of EBSD maps. <em>ODS-1-Ti_EBSD_IPF.bmp</em> and <em>ODS-2-TiV_EBSD_IPF.bmp</em> files are EBSD maps, which were used to create Fig. 9a and Fig. 9b.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of indentation sites:</span></strong><span> SEM images of indentation sites which were used to create Fig. 11c and Fig. 11d. </span></p> <p><strong><span><span>      3.<span>      </span></span></span></strong><strong><span>TEM</span></strong></p> <p><span>The TEM folder consists of two subfolders:</span></p> <p><span><span>·<span>        </span></span></span><strong><span>TEM of bulk samples:</span></strong><span> TEM/STEM images and data about precipitates (<em>Histograms data.xlsx</em>), which were used to create Fig. 7. </span></p> <p><span><span>·<span>        </span></span></span><strong><span>STEM EDS of bulk samples:</span></strong><span> In each subfolder (ODS-1-Ti and ODS-2-TiV), there are maps of the distribution of elements in both studied samples. These data were used to create Fig. 8.</span></p> <p><strong><span><span>      4.<span>      </span></span></span></strong><strong><span>Density:</span></strong><span> the<strong> </strong>folder contains a file with data related to the density measurements, which were used to create Table 3. </span></p> <p><strong><span><span>     5.<span>      </span></span></span></strong><strong><span>XRF:</span></strong><span> the folder contains two files related to XRF composition measurements. In the <em>XRF-graphs.docx</em> file, two plots are shown that are used to create Fig. 6. In <em>XRF_data.opju, </em>the data from the XRF device is shown. </span></p> <p><strong><span><span>     6.<span>      </span></span></span></strong><strong><span>Hardness:</span></strong><span> the folder contains a file with raw data of hardness measurements. </span></p> <p><strong><span>Nanoindentation:</span></strong><span> the folder contains two files, i.e., Nanoindentation.xlsx and Nanoindentation.opju, which contain nanoindentation data used to create Fig. 11a and Fig. 11b.</span></p&gt

Microstructure and phase investigation of FeCrAl-Y2O3 ODS steels with different Ti and V contents

<p><strong><span>Description of data:</span></strong><span> The data set consists of seven main folders. The data is divided into folders based on the technique used to obtain the data. </span></p> <p><strong><span><span>      1.<span>      </span></span></span></strong><strong><span>XRD</span></strong><span> </span></p> <p><span>The XRD folder consists of two subfolders: </span></p> <p><span><span>·<span>        </span></span></span><strong><span>XRD of powder</span></strong><span>: raw data from diffractometer, which were used to create Fig. 3.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>XRD of bulk samples</span></strong><span>: raw data from diffractometer, which were used to prepare Fig. 10.</span></p> <p><strong><span><span>      2.<span>      </span></span></span></strong><strong><span>SEM</span></strong></p> <p><span>The SEM folder consists of six subfolders:</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of powder:</span></strong><span> SEM images, which were used to create Fig. 1 showing powder morphology.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>EDS of powder:</span></strong><span> SEM images and EDS spectra (<em>p11.tif</em>, <em>p13.tif</em>, <em>p30.tif</em>, <em>p32.tif</em>), which were used to create Fig. 2, show the chemical homogeneity of the powder.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of bulk samples:</span></strong><span> SEM images of bulk samples that were used to create Fig. 4.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>EDS of bulk samples:</span></strong><span> it consists of two SEM images of the region of interest (i.e., ODS-1-Ti.tif and ODS-2-TiV) and two .docx files (i.e., <em>ODS-1-Ti.docx</em> and <em>ODS-2-TiV.docx</em>) with maps of distribution of chemical elements selected for the analysis. These data were used to create Fig. 5. </span></p> <p><span><span>·<span>        </span></span></span><strong><span>EBSD of bulk samples:</span></strong><span> This subfolder consists of several files. <em>ODS-1-Ti_EBSD_grain_leg_info.txt</em> and <em>ODS-2-TiV_EBSD_grain_leg_info.txt</em> files<em> </em>consist of data from the EBSD software, which enable us to create a histogram of grain size in Fig. 9c. <em>ODS-1-Ti_EBSD_info.txt</em>, <em>ODS-1-Ti_EBSD_leg.bmp,</em> and <em>ODS-2-TiV_EBSD_info.txt, ODS-2-TiV_EBSD_leg.bmp</em> files contain information about the acquisition parameters of EBSD maps. <em>ODS-1-Ti_EBSD_IPF.bmp</em> and <em>ODS-2-TiV_EBSD_IPF.bmp</em> files are EBSD maps, which were used to create Fig. 9a and Fig. 9b.</span></p> <p><span><span>·<span>        </span></span></span><strong><span>SEM of indentation sites:</span></strong><span> SEM images of indentation sites which were used to create Fig. 11c and Fig. 11d. </span></p> <p><strong><span><span>      3.<span>      </span></span></span></strong><strong><span>TEM</span></strong></p> <p><span>The TEM folder consists of two subfolders:</span></p> <p><span><span>·<span>        </span></span></span><strong><span>TEM of bulk samples:</span></strong><span> TEM/STEM images and data about precipitates (<em>Histograms data.xlsx</em>), which were used to create Fig. 7. </span></p> <p><span><span>·<span>        </span></span></span><strong><span>STEM EDS of bulk samples:</span></strong><span> In each subfolder (ODS-1-Ti and ODS-2-TiV), there are maps of the distribution of elements in both studied samples. These data were used to create Fig. 8.</span></p> <p><strong><span><span>      4.<span>      </span></span></span></strong><strong><span>Density:</span></strong><span> the<strong> </strong>folder contains a file with data related to the density measurements, which were used to create Table 3. </span></p> <p><strong><span><span>     5.<span>      </span></span></span></strong><strong><span>XRF:</span></strong><span> the folder contains two files related to XRF composition measurements. In the <em>XRF-graphs.docx</em> file, two plots are shown that are used to create Fig. 6. In <em>XRF_data.opju, </em>the data from the XRF device is shown. </span></p> <p><strong><span><span>     6.<span>      </span></span></span></strong><strong><span>Hardness:</span></strong><span> the folder contains a file with raw data of hardness measurements. </span></p> <p><strong><span>Nanoindentation:</span></strong><span> the folder contains two files, i.e., Nanoindentation.xlsx and Nanoindentation.opju, which contain nanoindentation data used to create Fig. 11a and Fig. 11b.</span></p&gt