PhD report (June 2013) K.Kubok
Monday, 8 July, 2013, 07:51 Posted by Katarzyna Kubok
My activities in June: During this month I have prepared publication entitled: Structural investigation of Mg-3Ca, Mg-3Zn-1Ca and Mg-3Zn-3Ca wt.% as cast alloys. Here you have an abstract: Magnesium alloys from Mg-Zn-Ca system are interesting, because of possible application as bioresorbable cardiovascular stents or temporary orthopaedic implants. Avoidance of removal surgery is an undeniable advantage of using biodegradable materials. Alloys of nominal composition Mg-3Ca, Mg-3Zn-1Ca and Mg-3Zn-3Ca (in wt.%) have been prepared by resistance melting and casting into graphite mould under protective argon atmosphere. All investigated alloys have revealed (Mg) dendritic microstructures with intermetallic phases distributed in interdendritic spacing. Except a(Mg), hexagonal ternary phase Ca2Mg6Zn3 has been detected for the Mg-3Zn-1Ca alloy and Mg-3Zn-3Ca (Ca2Mg6Zn3 phase belongs to the space group P63/mmc, with lattice parameters depending on the chemical composition). It was calculated that the unit cell parameters for the ternary phase change - a: from 9.912 to 9.945 Å, c: from 10.351 to 10.378 Å, if compare Mg-3Zn-1Ca to Mg-3Zn-3Ca. The Mg-3Ca alloy contain only Mg2Ca (hexagonal crystal structure; space group P63/mmc, with lattice parameters a = 6.239 Å and c =10.146 Å). The same binary phase has been identified in Mg-3Zn-3Ca alloy, but with slightly changed parameters: a = 6.2152 Å and c = 10.0699 Å. The hardness of all alloys have been measured. The highest value: 68 HV has been observed for Mg-3Zn-3Ca alloy whereas hardness of alloy containing only calcium was significantly lower: 49 HV. Both existing in materials intermetallic phases segregate on the grain boundaries and harden alloys.
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"
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