PhD report (June 2013) J.Poplewska
Saturday, 6 July, 2013, 14:46 Posted by Jagoda Poplewska
Based on the results of the research of local orientations measured by EBSD/SEM for AA1050 and AA3004 aluminum alloys (made in the system y-x: for cross-section ND-TD or TD-ND) I made studies of transformation of these data into rolling system TD-RD and I created a tool to verify correctness of these transformations. Based on the analysis of texture data for the calculated percentage shares texture components defined as: 'Copper','S', 'Goss','Brass',I could draw the following conclusions: - You can get data on percentage shares of individual texture components in the rolling system (for plane TD-RD) by performing measurements of local orientation (EBSD maps) in a plane perpendicular to the RD direction (RD is parallel to ED in ECAP die) and transforming it accordingly; - The analysis of change of texture components in function of 1-hour annealing temperature (from 100°C to 400°C) for AA1050 and AA3004 aluminium alloys showed no correlation (too small region taken to the measurement); - To obtain reliable data, the measurement should be made over a larger area - should cover a wider range of microstructure (our area was 10x10µm2); - Verification of the results should always be made based on a different method of measurement, in our case, we will survey the entire surface of the sample using X-ray diffractometer.
PhD report G. Kulesza (June'13)
Friday, 5 July, 2013, 10:14 Posted by Grazyna Kulesza
I decided to deal with the heat of my solutions. Cooling them were not so easy. I found that the labortory refrigerator had cooled my reagents to 17 degrees C (at room temperature over 25). The effect was pour - a little smaller pits on the surface. I'm looking for a better way of effective mixture cooling. The second thing was etching the nanoporous layer with 1 M KOH. After that, the nicely textured wafers with low reflectivity, returned to the base materials reflectivity of more than 30%, what troubled me a lot. Generally, this month was not really successful...
Friday, 5 July, 2013, 09:19 Posted by Pawel Czaja
In July let me think...Oh I forgot to mention in my previous entries that I attended the AMT Phys Metall conference in Kudowa Zdrój, where I gave a talk on the evolution of microstructure and its impact on phase transtions in Heusler Ni-Mn based alloys. It was well received ang gave me encouragement for further research.
Thursday, 4 July, 2013, 14:40 Posted by Jakub Kawalko
In June I attended international conference "XX Physical Metallurgy and Materials Science Conference Advanced Materials and Technologies AMT 2013" organised by Institute of Materials Science of Czestochowa University of Technology in Kudowa Zdrój. During the conference I have presented a talk entitled "Microstructure of commercial purity titanium subjected to complex loading by the KoBo method"
Thursday, 4 July, 2013, 14:29 Posted by Piotr Drzymala
Samples were examined by electron microscopy SEM, recording the success of EBSD map of the sample surface. The map was exported to a text file and loaded into the program Mathematica. Unfortunately, the map was created in a hexagonal grid (arrangement of pixels) and not orthogonal, hence the need to jog every other row of one element, but the difficulty was easily overcomed. Each pixel was colored by transforming the three Euler angles describing the orientation (φ1, Φ, φ2) in the rotation matrix, which is used to rotate the vector N = {0,0,1} crystallite in the system, which then discharges stereographic full inverse pole figure and the position of the RGB color line calculated in manner = {1-r (1-theta / (pi / 6)) * y (theta / (pi / 6)) * y}, bringing the advance angle theta to the base area. Digression: the pole figure on the reverse orientations are operating on the system, expressed in crystallite S-> C, and not in the sample circuit C-> S, as is the case with the convention rotation matrix. However, for our purposes, we use this time active matrix rotation (rotate vectors) rather than as simply passive (when the system is rotated). Therefore, if the passive rotation matrix in the system the sample is g, this passive rotation matrix in the system of the crystallites to g ^ T, and the active matrix circuit circulation of the crystallites is g = g ^ TT
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