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RESEARCH ARTICLES

DOI: 10.15199/40.2018.12.1

Application of nanofiller based on halloysite mineral in anticorrosive paints

KUCZYŃSKA H.

Instytut Inżynierii Materiałów Polimerowych i Barwników, Oddział Farb i Tworzyw, Gliwice

The influence of new halloysite nanofiller on the properties of solvent-borne and water-borne anticorrosive paints containing an active anticorrosive pigment (zinc phosphate) or pigment of barrier activity (micaceous iron oxide) was investigated. A nanofiller obtained from the processing of halloysite mine from “Dunino” deposits were used for preparation of paints. The reduced pigments and fillers volume concentration, Λ, for solvent-borne paint formulations was equal on the level of 0,72 and for waterborne paints was different: 0,48; 0,58 and 0,72. It was proved that application of nanofiller and micaceous iron oxide, as a result of their synergic action, provides better protection against corrosion in comparison with paints based on zinc phosphate (especially for water-borne paints).

Keywords: halloysite, anticorrosive pigments, anticorrosive paints, water-borne paint, mine from deposit of “Dunino”

2018, Vol. 61, nr 12, s. 358-362

Ref. 21

DOI: 10.15199/40.2018.12.2

Conductive polymers in corrosion protection

ADAMCZYK A.

Katedra Chemii, Wydział Inżynierii Procesowej, Materiałowej i Fizyki Stosowanej, Politechniki Częstochowskiej

Particular considerations has been given in recent years to the design and preparation of new coatings intended to protect metals against corrosion. This effort is partially motivated by the wish to replace chromate coatings used for the corrosion protection of iron an aluminium alloys. It has been proved that chromium poses a threat to the natural environment and human health, and its use will be radically reduced in many countries in the years to come. Electroactive conductive polymers represent a class of interesting materials to be used in the form of corrosion protective coatings, and it is probably them or composite systems based on them that will replace chromate coatings. Just like chromate coatings, conductive polymers exhibit an interesting and potentially advantageous influence on active alloys, causing a change in their corrosion behaviour. Unique properties of conductive polymers (ECP), such as physicochemical stability, relatively easy fabrication, modifiability and good conductivity, distinguish them from traditional organic coatings. The most often examined polymer coatings include polyaniline (PANI), polypyrrole (PPy) and polythiophenes, because of their susceptibility to modification and ease of obtaining [1-3]. This article provides a review of literature outlooks for using conductive polymerbased coatings in corrosion protection.

Keywords: conductive polymers, electrochemistry, corrosion

2018, Vol. 61, nr 12, s. 363-368

Ref. 92

DOI: 10.15199/40.2018.12.3

The numerical analysis of stress and temperature distribution in a double-ceramic-layer (DCL) type of La₂Zr₂O₇/8YSZ thermal barrier coatings (TBC) in as-sprayed state

JASIK A.

Silesian University of Technology, Institute of Materials Engineering, 40-019 Katowice, Krasińskiego Street 8, Poland

The paper presents the results of numerical calculations of the temperature distribution and thermal stresses in two systems of layered thermal barrier coatings (TBC) of DCL (double-ceramic--layer) type deposited on the In625 Ni-based superalloy by atmospheric plasma spraying (APS). Conventional monolayered TBC obtained from 8YSZ (6-8% wt. Y₂O₃×ZrO₂) and LZO (La₂Zr₂O₇) powders with an insulation layer thickness of 300 μm was used as the reference material. Numerical analysis was applied to the DCL TBC systems in which the external ceramic layer was obtained from LZO powder, while the internal layer was a 8YSZ zone. The thickness of both types of ceramic sublayers was a variable parameter. In all cases it was assumed that the bond-coat would be the NiCrAlY type of coating obtained by atmospheric plasma spraying. The thickness of the bond-coat layer was 200 microns. The starting point was a TBC system with the same thickness of both zones (150 μm each), while further variants included coatings with the following mutual ratios of thickness of both materials (sub-layers):20/80, 30/70, 50/50, 70/30 and 80/20. The purpose of these analyses was to determine the optimum value of the thickness ratio of individual ceramic zones in DCL coatings, not only from the point of view of the insulation effect, but primarily the state of stresses determining the durability of the entire TBC system. Numerical analysis of stress and temperature distribution indicates that the life cycle of DCL coatings should be strongly dependent on the thickness ratio of ceramic zones LZO and YSZ, while the two-layer coatings show better aggregate insulation characteristics and related stress states.

Keywords: thermal barrier coatings (TBC), temperature distribution, thermal stress, FEM, double-ceramic-layer (DCL)

2018, Vol. 61, nr 12, s.369-374

Ref. 19

DOI: 10.15199/40.2018.12.4

Thermal diffusion zinc coating technology with reactive atmosphere recirculation.

Part 2: Corrosion resistance of coatings

KANIA H.

Politechnika Śląska, Gliwice, Instytut Inżynierii Materiałowej, ul. Krasińskiego 8, 40-019 Katowice

SIPA J.

REMIX S.A., ul. Poznańska 36, 66-200 Świebodzin

SKUPIŃSKA A.

Politechnika Śląska, Gliwice, Instytut Inżynierii Materiałowej, ul. Krasińskiego 8, 40-019 Katowice

The article presents the results of research into corrosion resistance of coatings obtained by an innovative method of thermal diffusion zinc coating with recirculation of reactive atmosphere. The structure of coatings is demonstrated and the thickness of individual layers is defined. Corrosion resistance of thermal diffusion coatings was defined comparatively through standard corrosion tests in neutral salt spray and in wet atmosphere containing SO₂. Conventional hot-dip zinc coating was used as reference coating. Salt chamber testing was conducted according to the standard PN-EN ISO 9227 while research in Koesternich chamber was performed in accordance with the standard PN-EN ISO 6988. It was determined that thermal diffusion coatings demonstrated very good corrosion resistance in the researched environments, better than the one obtained for hot-dip coatings. The high corrosion resistance of thermal diffusion coatings is the effect of forming an advantageous structure and increased thickness of Γ₁ and δ₁ phase layers within the coating.

Keywords: thermal diffusion zinc coating, hot-dip galvanizing, zinc coating, sherardizing

2018, Vol. 61, nr 12, s.375-382

Ref 16

DOI: 10.15199/40.2018.12.5

Effect of the preparation of the surface layer of iron alloys on the mechanical properties of anti-corrosion coatings

SKOTNICKI W.

JĘDRZEJCZYK D.

Akademia Techniczno-Humanistyczna w Bielsku-Białej, Wydział Budowy Maszyn i Informatyki, Katedra Podstaw Budowy Maszyn

DYRLAGA M.

„Metalpol”, Węgierska Górka; Akademia Górniczo-Hutnicza w Krakowie, Wydział Odlewnictwa

The paper attempts to determine the influence of high temperature oxidation as a method of preparing the surface of gray cast iron grade GJL-250 on the mechanical properties of the zinc coating obtained by the method of: hot-dip, galvanic and lamella. Samples for testing were taken from parts used for the construction

of overhead power lines. Intensity of wear of the zinc coating was determined by tribological tests under dry friction conditions, which were made using the T-11 tester. The research allowed to determine the coefficient of friction of the zinc coating depending on the method of preparation of the surface on which they were applied. In addition, macroscopic and microscopic analysis was performed to determine the mechanisms of shell damage and measurements of the geometric structure of the surface were made. On the basis of the obtained test results, the differentiation of the degree of wear of the obtained coatings was determined depending on the method of surface preparation. The conducted research has shown that the use of high temperature oxidation as a way of preparing the surface of gray iron can be a tribological characteristic of the zinc coating.

Keywords: zinc coatings, cast iron, tribological tests, high temperature oxidation

2018, Vol. 61, nr 12, s.383-386

Ref. 8