Wyniki wyszukiwania - BazTech

1

The Influence of the Microstructural Evolution on the Corrosion Resistance of Cold Drawn Copper Single Crystals in NaCl

Koralnik M., Dobkowska A., Adamczyk-Cieslak B., Mizera J.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 1

55--64

EN

The aim of the present work was to determine the influence of the microstructural evolution of copper single crystals with the initial orientations of <001> and <111> after cold drawing on their corrosion resistance. Transmission electron microscopy, X-ray diffraction, and electron backscattering diffraction were used to characterize the microstructural changes. To evaluate the corrosion resistance after deformation, open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization analyses were conducted. The microstructural observations showed the presence of dislocation cell structures and shear bands indeformed sample with initial orientation <001> single crystal, as well as a strongly-developed substructure in sample <111>. The material with initial orientation of <001> was more resistive in analyzed medium than material with the initial orientation of <111>.

2

Nickel Composite Coatings Reinforced Nano SiC Particles

Nowak M., Mizera J., Kłyszewski A., Dobkowska A., Boczkal S., Kozik A., Koprowski P.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 2

935--940

EN

The paper presents the results of the electrodeposition of nickel composite coatings reinforced with the nano size SiC ceramic particles. The type and size of the ceramic particles or organic additives used play a important role during electrodeposition processes. A Watts type galvanic bath with various organic additives was used. These additives were: 2-sulfobenzoic acid imide, dioctyl sulfosuccinate sodium salt (DSS), sodium dodecyl sulfate, tris (hydroxymethyl) aminomethane and hexamethyldisilizane. The nickel composite coating was electrodeposited on a 2xxx aluminum alloy series substrate (EN-AW 2017) with zinc interlayer. The work concerns the determination of the impact of the change in the zeta potential of SiC nanoceramic particles used on properties of composite coatings (wear resistance, corrosion, etc.). The paper characterized the composite nickel coatings on aluminum alloy using SEM techniques, wear resistance tests by TABER method and coating adhesion to the substrate using the “scratch test” method. The corrosion resistance of coatings was also tested using electrochemical methods. The research allowed to determine the effect of SiC nanoceramic particle size on the value of the zeta potential in the model KCl solution.

3

Effect of Various Organic Additives in Galvanic Bath on Properties of Ni-SiC Composite Coatings

Nowak M., Mizera J., Kłyszewski A., Dobkowska A., Boczkal S., Kozik A., Koprowski P.

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 4

1327--1333

EN

The paper presents the results of the electrodeposition of nickel composite coatings reinforced with the ceramic SiC particles. A Watts type galvanic bath modified with various organic additives was used. These additives were: 2-sulfobenzoic acid imide (LSA), dioctyl sulfosuccinate sodium salt (DSS), sodium dodecyl sulfate (SDS), tris (hydroxymethyl) aminomethane (THAM) and hexamethyldisilizane (HMDS). The nickel composite coating was electrodeposited on a 2xxx aluminum alloy series substrate (EN-AW 2017) with zinc interlayer. Studies concerned the effect of the applied organic additives on properties of composite coatings such as: microstructure, microhardness, adhesion to the substrate, corrosion resistance and roughness. The structure of the coatings was assessed by scanning electron microscopy and light microscopy. Based on the studies of zeta potential it was found that the bath modification had a significant impact on the amount of the ceramic phase embedded in metal matrix. The tests conducted in a model 0.01 M KCl solution were not fully representative of the true behavior of particles in a Watts bath.

4

Rozdział 6. Dobór materiałów orurowania odwiertów na bazie oceny kinetyki degradacji

Dobkowska A., Ura-Bińczyk E., Solarski W., Mazurkiewicz B., Banaś J., Mizera J.

Prace Naukowe Instytutu Nafty i Gazu

|

2018

|

nr 223, t. 2

12--77

EN

Chapter VI includes a wide range of microstructure description of steels (carbon steels: K55, N80-1, highly alloyed H13 and stainless steel 316) and composites (GRE — Glassfibre Reinforced Epoxy and HDPE — High-Density Polyethylene), and its influence on their corrosion resistance, leading to elaboration of the database of materials used in the shale gas production system due to their kinetics of degradation. In this Chapter, the modern methods within the study of electrochemical and mechanical properties of selected materials were used. The mechanism and kinetics of corrosion and erosion degradation were measured using electrochemical DC methods (LPR, LSV, potentiostatic and galvanostatic), AC methods — electrochemical impedance spectroscopy (EIS), gravimetric methods and morphological studies of material degradation with the use of image analysis. The composition and structure of corrosion products were investigated by XRD technique, FTIR spectroscopy, and SEM followed by EDS analysis. The Authors focused on four main tasks, the first one included the description of research on the corrosive-erosive wear resistance of steel and composite materials in the crevice fluid and the second comprised of the research on the corrosion resistance of steel and composite materials in the H2O-CO2-H2S atmosphere. The third part of the results presented in this chapter related to the microbiological corrosion resistance SRB (Sulfate Reducing Bacteria) of steel and composite materials in the H2O-CO2-H2S atmosphere. An important part of the investigations described in Chapter 6 was to make the comparison of the corrosive behaviour of steels, which are in frequent use in the shale-gas production system, and composites under the neutral salt spray conditions. Based on the above mentioned experiments, the authors compiled an extensive data- base, where a broad description of corrosion resistance of materials for shale-gas production systems is included. The matching of microstructural features with corrosion resistance and mechanical properties of various types of steel and new generation composite materials would have a strong influence on future experiments conducted in such a common aspect in the shale-gas production system, as materials degradation is.

5

Ocena wpływu niezgodności położenia działów wód podziemnych i powierzchniowych na wielkość obliczonych zasobów odnawialnych na przykładzie obszaru bilansowego P-IX w regionie wodnym Warty

Wieteska Z., Dobkowska A.

Biuletyn Państwowego Instytutu Geologicznego

|

2018

|

nr 471, Hydrogeologia, z. 15

185--191

PL

W artykule przedstawiono rezultaty badań odnawialności wód podziemnych systemu wodonośnego, który charakteryzuje znaczna niezgodność położenia wododziałów wód powierzchniowych i podziemnych. Rozpoznanie warunków hydrogeologicznych i hydrologicznych oraz bilans zasobów wód podziemnych sporządzono dla fragmentu obszaru bilansowego P-IX (Warta od Prosny do Kanału Mosińskiego) usytuowanego na południe od rzeki Warty. Obliczenia bilansowe wykonano metodą modelowania matematycznego oraz hydrologiczną. Ponieważ w metodzie hydrologicznej stanowiącej powszechnie stosowaną metodę kontrolną w obliczeniach bilansowych zakłada się, że linie wododziałów wód powierzchniowych i podziemnych są tożsame, porównanie wyników obliczeń bilansowych uzyskanych obiema metodami wymagało przeprowadzenia oceny ich zgodności. Dokonano tego poprzez obliczenie różnicy między wielkościami zasobów odnawialnych wyznaczonych dwoma wariantami metody hydrologicznej. W pierwszym (standardowym) zasoby odnawialne określono na podstawie danych z profili wodowskazowych i hydrometrycznych zamykających zlewnie dopływów Warty drenujących analizowaną jednostkę bilansową. W drugim (rozszerzonym) obliczono na podstawie danych z posterunków kontrolujących zlewnię różnicową Warty. Powiększenie bilansowanej jednostki do granic zlewni różnicowej Warty było zgodne z zasadą, że wiarygodność obliczeń zasobów wód podziemnych rośnie proporcjonalnie do powierzchni bilansowanej zlewni oraz znaczenia jej strefy drenażu w krążeniu regionalnym (Toth, 1963). Wielkość zasobów odnawialnych określona standardowym i rozszerzonym wariantem metody hydrologicznej wyniosła odpowiednio: 107,1 tys. i 184,0 tys. m3/d. Różnica stanowi 72% wartości wyznaczonej metodą standardową. W artykule analizowano ponadto zmienny, w przestrzeni i czasie, charakter związku hydraulicznego wód powierzchniowych i podziemnych oraz wpływ tej zmienności na wiarygodność obliczeń bilansowych, bazujących na stacjonarnych obserwacjach przepływu wód powierzchniowych.

EN

The article presents the results of research on the renewal of a hydrogeological system that is characterized by a significant discrepancy of the location of groundwater and surface watersheds. The area of the hydrological and hydrogeological studies is part of the P-IX balance region (Warta River from the Prosna to the Mosiński Canal) located south of the Warta River. The evaluation of groundwater renewability has been made using a hydrological method and mathematical modelling. When using the hydrological method, which is a commonly used control method for water balance calculations, it is assumed that the surface and groundwater watersheds are identical. Comparison of the results of water balance calculations obtained with both methods required the assessment of the compatibility of the groundwater catchment and morphological boundaries. This was done by calculating the difference between the quantities of renewable resources determined by two variants of the hydrological method. In the first (standard) variant, renewable resources were determined based on data from water-gauge and hydrometric profiles closing the catchments of the Warta tributaries draining the analyzed water-management regions. In the second (extended) method, they were determined based on data from water gauges controlling the Warta sub-basin. Enlargement of the balanced unit as far as the boundaries of the Warta basin was consistent with the principle that the reliability of calculations of groundwater resources increases proportionally to the analyzed catchment area and the significance of its drainage zone in the regional groundwater circulation (Toth, 1963). The quantity of renewable resources determined by the standard and extended variants of the hydrological method amounted to 107,100 m3/day and 184,000 m3/day, respectively. The difference is 72% of the value determined using the standard method. The article also provides an analysis of the spatial and temporal variability of the nature of the hydraulic relationship between surface water and groundwater, and the influence of this variability on the reliability of water balance calculations, based on stationary observations of surface water flow.

6

Influence of the corrosive environment on the Portevin–Le Chatelier plastic instability phenomenon in Al–1Mg and Al–3Mg model alloys

Towarek A., Zdunek J., Mizera J., Dobkowska A., Molak R.

Inżynieria Materiałowa

|

2016

|

Vol. 37, nr 3

98--103

EN

The aim of this work was to indicate the influence of changes on the surface of materials caused by the corrosive medium (3.5% NaCl solution) on the intensity and character of the Portevin–Le Chatelier effect in model aluminium alloys. For this purpose, two Al alloys, containing 1% and 3% of magnesium, were subjected to tensile testing in the as-cast state and after the exposition in NaCl solution for various time. Several electrochemical measurements were held to determine materials’ corrosive behaviour and microscopic observations to evaluate the surface character of the samples. High corrosion resistance of the materials resulted in a very slight alteration of their surface development, which didn’t lead into any significant variations in the plastic instability phenomenon PLC.

PL

Efekt Portevin–Le Chatelier jest dobrze znanym i szeroko opisanym zjawiskiem pojawiającym się w wielu stopach aluminium. Objawia się on podczas odkształcania w postaci charakterystycznych ząbków na krzywej rozciągania wywołanych gwałtownymi zmianami naprężenia przy niewielkim odkształceniu. Wpływ na to zjawisko jest przypisywany głównie czynnikom wewnętrznym, wynikającym ze struktury materiału, takim jak: wielkość ziarna, obecność wydzieleń czy tekstury. Istotne mogą być jednak również czynniki zewnętrzne, m.in. szybkość odkształcania, środowisko czy stopień rozwinięcia powierzchni próbki. Celem pracy było zbadanie, jak zmiany na powierzchni materiału wywołane przez ekspozycję w środowisku korozyjnym (3,5% roztworze NaCl) wpłyną na intensywność i charakter zjawiska Portevin–Le Chatelier w dwóch modelowych stopach aluminium, Al–1Mg oraz Al–3Mg.

7

The Development of Rapidly Solidified Magnesium – Copper Ribbons

Pastuszak M., Cieślak G., Dobkowska A., Mizera J., Kurzydłowski K. J.

Archives of Metallurgy and Materials

|

2016

|

Vol. 61, iss. 2B

1083--1088

EN

The aim of the present work was to plan and carry out an experiment consisting of amorphization of industrial magnesium alloy WE 43 (Mg - 4 Y - 3 RE - 0.5 Zr) modified by the copper addition. Investigated alloy modified with 20% of copper was rapidly quenched with the use of melt spinning technique. The effects of cooling rate on the structure and properties of the obtained material were extensively analyzed. The structure and phase analysis of samples were examined using X-ray diffraction method (XRD) while the thermal stability of the samples was determined by differential scanning calorimetry (DSC). Microstructure observations were also conducted. The microhardness tests (HV0.02) and corrosion resistance tests were carried out to investigate the properties of the material. Corrosion resistance measurements were held using a typical three-electrode system. As the result of the research, the effect of cooling rate on microstructure and properties of investigated alloy was determined.

8

The Comparison of the Microstructure and Corrosion Resistance of Sand Cast Aluminum Alloys

Dobkowska A., Adamczyk–Cieślak B., Mizera J., Kurzydłowski K. J., Kiełbus A.

Archives of Metallurgy and Materials

|

2016

|

Vol. 61, iss. 1

209--212

EN

The influence of different types of precipitation on the corrosion behavior was investigated in three aluminum-siliconmagnesium alloys. The microstructures of the alloys were studied through optical (OM) and scanning electron microscopy (SEM). The structures consisted of an α-Al solid solution matrix, Si eutectic crystals, secondary phases AlFeSi and AlMgFeSi (Chinese script), as well as Mg2Si. The corrosion behavior was examined with the use of a potentiodynamic polarization test followed by a SEM surface analysis. The results indicate that all the analyzed samples were in the passive state and AlSi10Mg was less reactive in the corrosive environment.

9

Modelowanie matematyczne i badania fizykochemiczne równowag kwasowo-zasadowych w układach binarnych rozpuszczalników

Michałowski T., Pilarski B., Dobkowska A., Młodzianowski J.

Wiadomości Chemiczne

|

2010

|

[Z] 64, 1-2

123-154

EN

Conductometric titration (CT) is used as a complementary, non-specific technique against potentiometric (pH) titration (PT). The CT + PT procedure is applied to binary-solvent systems: HmL + Z/A + B (or HmL + Z/W + B) formed of a weak acid HmL and a pH-modifying agent Z (e.g. NaOH, NH3 or HCl), and totally miscible organic solvents A and B (or W = H2O and B) chosen as co-solvents, where acid-base equilibria are considered. The solvent composition in such systems is expressed by the mole fraction x of B. Concentrations of solutes: HmL and Z are the same in the solution titrated (titrand, D) and in titrant (T) and changes in pH value resulted only from differences in acid-base properties of solvents applied in D and T. On the basis of results obtained from PT and CT, the functional relationships related to the solutions of weak acids HmL (m = 1, 2, ...) were formulated, namely: (1) pKi = pKi(x) for acidity parameters; (2) Lp = Lp(x) for molar conductivities, related to the species formed by di- and triprotic acids. For this purpose, the Kohlrausch law on the independence of migrating ions has been applied. The pKi = pKi(x) relationships were formulated for diprotic and triprotic acids on the basis of enderson.Hasselbalch functions and modeled with use of polynomial functions. The pKi(1) and Lp(1) values were obtained by extrapolation. The approach suggested is the essential novelty in contemporary literature related to the subject in question. This way, the paper provides a new methodology, a new dimension (x-scale) to the problems known hitherto. In the experimental part, the pK1 = pK1(x) relationships were formulated for results of mutual pH titrations: HmL/B . HmL/W or HmL/B . HmL/A, obtained for the systems not involving Z. The systems were modeled with the use of Redlich.Kister (R.K) and orthogonal (normal, shifted) Legendre polynomials. Asymmetric functions by Myers.Scott (M.S) and by Michałowski were also suggested for this purpose. It was stated that all approximating functions fit the experimental data very well. The asymmetric functions are applicable for modeling of more bended relationships pK1 = pK1(x), particularly when referred to the limiting x-values in the interval < 0, 1 >. A software that enables to formulate the relationships pKi = pKi(x) according to different approximating functions after introducing the experimental data {(Vj, pHj) | j = 1, ..., N} obtained from PT, was also prepared, together with statistical evaluation of pKi(0) and pKi(1) values, obtained by extrapolation. The results thus obtained are presented in tables and figures. Some criteria of validity of the results obtained according to PT for pK1(0) and pK1(1) are also presented. The first criterion testifying about reversibility of indications of the measuring system is a position of the point of intersection of the plots obtained in the mutual titrations. The second criterion stems from comparison of results obtained from three pH titrations: (1) HmL/B Ť HmL/W, (2) HmL/B Ť HmL/A and (3) HmL/A Ť HmL/W. The convergence of the related plots at x = 0 and x = 1, where x = xB in (1) and (2) and x = xA in (3) testifies on account of the calibration procedure applied for glass electrode.