C. Senderowski - Academia.edu (original) (raw)

Papers by C. Senderowski

Coatings

The aim of this study was to determine the suitability of arc sprayed zinc and aluminum coatings ... more The aim of this study was to determine the suitability of arc sprayed zinc and aluminum coatings as materials for protective coatings of different heating systems. The most aggressive chemical agents occurring in heating water are chloride and sulfate anions. Both ions are responsible for the corrosion of metals due to their high electronegativity and standard electrochemical potential. Water in heating systems should not contain more than 150 mg/L anions, including no more than 50 mg/L of chlorides and 100 mg/L of sulfates. To determine the corrosion resistance of three types of zinc and aluminum coatings, open circuit potential and linear polarization resistance (LPR) tests were conducted in eight alkaline solutions with different sulfate and chloride contents. The SEM/EDS structural properties of sprayed coatings at specific arc process parameters were investigated. Zinc coatings exhibit the most stable corrosion potentials in varying environments but have higher corrosion curren...

Materiały Wysokoenergetyczne, 2016

Purpose: An analytical model is provided in order to reveal the mechanism of the intermetallic mu... more Purpose: An analytical model is provided in order to reveal the mechanism of the intermetallic multi-layer formation on a substrate. Thus, formations of the Al3Ni2 – Al3Ni intermetallic multi-layer on the Ni – substrate and Fe3Zn10 – FeZn10 – FeZn13 intermetallic multi-layer on the Fe (armco) multi-layer are considered.Design/methodology/approach: The intermetallic multi-layers are the products of the undercooled peritectic reactions as this results from the model. Back-diffusion and partitioning as the phenomena accompanying the peritectic reactions are employed to describe the sub-layers growth.Research limitations/implications: The model could be modified to describe the multi-layers formation under the metastable conditions.Practical implications: The modeled descriptions of the mechanism of multi-layer formation seems to be a good tool to control the technologies like: diffusion soldering / brazing or hot dip galvanizing into zinc bath.Originality/value: This is quite new model...

Journal of Thermal Spray Technology, 2014

The nanocomposite structure of Fe-Al intermetallic coating, created in situ during gas detonation... more The nanocomposite structure of Fe-Al intermetallic coating, created in situ during gas detonation spraying (GDS) of as-milled self-decomposing powder and containing disordered 8 nm FeAl nanocrystals, was analyzed using scanning electron microscopy (SEM) with energy-dispersive x-ray (EDX) spectroscopy, transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and x-ray diffraction methods. It is found that the Fe-Al coating is characterized by a sublayer morphology consisting of flattened and partially melted splats containing a wide Al range from about 26 to 52 at.%, as well as Al 2 O 3 oxides, created in situ at the internal interfaces of splats during the GDS process. The complex oxide films, identified as amorphous Al 2 O 3 , which are formed in the nanocrystalline Fe-Al matrix of the GDS coating behave like a composite reinforcement in the intermetallic Fe-Al coating. The combined presence of nanosized subgrains in the Fe-Al matrix and the Al 2 O 3 nanoceramic dispersoids significantly increases the microhardness of the coating. Keywords Gas detonation spraying, multiphase nanocomposite coating (based on FeAl), nanocrystalline self-decomposing powder Dedicated to the memory of Professor George Bystrzycki, a half year after his death.

The paper presents results of a research on simulation of magnetic tip-surface interaction as a f... more The paper presents results of a research on simulation of magnetic tip-surface interaction as a function of the lift height in the magnetic force microscopy. As expected, magnetic signal monotonically decays with increasing lift height, but the question arises, whether or not optimal lift height eventually exists. To estimate such a lift height simple procedure is proposed in the paper based on the minimization of the fractal dimension of the averaged profile of the MFM signal. In this case, the fractal dimension serves as a measure of distortion of a pure tip-surface magnetic coupling by various side effects, e.g. thermal noise and contribution of topographic features. Obtained simulation results apparently agree with experimental data.

Coatings, 2018

The medium and high temperature tribological behavior of different iron aluminide thermal spray c... more The medium and high temperature tribological behavior of different iron aluminide thermal spray coatings was investigated. Several powders synthesized through different routes (ball milling, self-decomposition, and self-propagating high-temperature sintering (SHS)) were evaluated. High heterogeneity of conventional High Velocity Oxygen Fuel (HVOF) coatings plays a vital role in their sliding performance, but as long as their integrity is preserved under high temperature oxidizing conditions, the wear rates are found to be acceptable, as it occurs in the case of ball milled Fe-40Al (at.%) powder. The friction phenomenon and wear mechanisms were analyzed in detail through the wear track morphology, contact surface, and friction coefficients. The occurrence of brittle phases in the sprayed coatings, which are also present when tested at high temperatures, appeared to be crucial in accelerating the coating failure.

A thermodynamic justification for the joint formation is developed on the basis of the diffusion ... more A thermodynamic justification for the joint formation is developed on the basis of the diffusion brazing of the Ni/Al/Ni system. The phenomena of dissolution and solidification were included into the description. The first solid/solid transformation is also discussed. Mainly, a description for the isothermal brazing occurrence in the meta-stable conditions is developed. It involves the application of the criterion of higher temperature of the solid / liquid (s/l) interface. The dissolution of the filler metal in the substrate is described by the N0 – solute concentration within the dissolution zone (liquid film) distinguished at the substrate surface. The selection of the N0− parameter by the dissolution is justified by the Thermocalc calculation of the Ni-Al phase diagram for meta-stable equilibrium. According to the model assumptions, the solidification is accompanied by partitioning or by undercooled peritectic reaction resulting in formation of the intermetallic phase. The avera...

ABSTRACT A modified Sachs method was applied to determine the residual surface stress in Fe-Al ty... more ABSTRACT A modified Sachs method was applied to determine the residual surface stress in Fe-Al type intermetallic coatings deposited on a surface of carbon 1045 steel substrate by a gas detonation spray technique. The detailed theoretical model with a description of device is presented. Compressive stresses in the entire thickness of created coatings is discussed. The influence of chemical composition of powders (applied for coating deposition) on residual stress related to the structural and phase composition, as well as the degree of chemical heterogeneity of the multilayer composite coating system is analyzed. The maximum amplitude of stress on the surface of coatings is within the range of −900 to −1100 MPa for samples without boron additive and between −500 and −600 MPa for samples with boron only. The composition of the powder blend of the FeAl-intermetallic coatings deposited on the surface of the substrate affects significantly the distribution of residual stresses. The structural inhomogeneity and no repeatability of physical and chemical properties of particular structural elements are the reasons for the development of residual stresses system generation within the coating.

Intermetallics, 2010

ABSTRACT Intermetallic Fe–Al type coatings about 100 μm thick were deposited on a plain carbon st... more ABSTRACT Intermetallic Fe–Al type coatings about 100 μm thick were deposited on a plain carbon steel substrate by D-gun spraying technique. The 40–75 μm size fraction of the feedstock powder was obtained by self-propagating high-temperature synthesis and sieved prior to D-gun spraying. This powder contained a mixture of Fe–Al type intermetallic phases conventionally appointed FexAly. The Fe–Al coatings were analysed by transmission electron microscopy, selected area electron diffraction, and semi-quantitative energy-dispersive X-ray analysis in micro-areas. Particular attention was paid to the substructure of the individual grains in the coating zone abutting the steel substrate. The Fe–Al coatings have a multi-layer composite structure. The results explain the formation mechanism of the coating microstructure. The powder particles, which were heterogeneous in chemical composition and structure, were heated, highly softened or even partially melted and oxidised while flying from the gun barrel to the substrate. After impacting the substrate or previously deposited material and being shot peened by the following powder particles, they were rapidly cooled and plastically deformed, creating overlapping splats. In the zone adjacent to the substrate, alternating FeAl and Fe2Al5 intermetallic phases formed columnar crystals. The columnar crystal areas were separated by elongated amorphous oxide layers. Areas of mixed equiaxed subgrains of FeAl and Fe3Al phases, fine grains of Fe-rich Fe(Al) solid solution, and micro- and nano-pores were also present.

Archives of Metallurgy and Materials, 2010

The microstructure of transition layers of Ni(Al)-pure Ni with Al and NiAl particles as well as C... more The microstructure of transition layers of Ni(Al)-pure Ni with Al and NiAl particles as well as Cr(Ni)-pure Cr in the Ni matrix, occurred between the coating of Fe-Al type intermetallic phases and the 045 carbon steel substrate was analysed in the present work. The investigations were aimed at the adherence of transition layers and the outer coating deposited with the detonation-gas spraying. The structure was examined using the methods of scanning (SEM) and transmission electron (TEM) microscopies as well as the analysis of chemical composition in microareas (EDS). Silica grains at the boundary of the substrate and the layer of Ni(Al), aluminium oxide at the boundary and inside the Ni(Al) layers, an Al based AlNiO x phase, columnar crystals at the boundary of the coating of Fe-Al type phases and an adjacent Cr(Ni) layer were observed. The results were discussed in reference to earlier examinations of bending strength considering cracking and delamination of the coating off the substrate. They were then compared with the state of the boundary between the coating and the steel substrate analysed in former works. It seems, that the substrate boundary free from silica inclusions and the prevention of the formation of aluminium oxides at the boundary of transition layers and the substrate should improve the adherence of the whole multi layer and the coating.

Materials, 2015

The detonation gun sprayed Fe-Al type coatings as an alternative for austenitic valve steel, were... more The detonation gun sprayed Fe-Al type coatings as an alternative for austenitic valve steel, were investigated using two different methods of testing corrosion resistance. High temperature, 10-hour isothermal oxidation experiments at 550, 750, 950 and 1100 °C show differences in the oxidation behavior of Fe-Al type coatings under air atmosphere. The oxide layer ensures satisfying oxidation resistance, even at 950 and 1100 °C. Hematite, α-Al2O3 and metastable alumina phases were noticed on the coatings top surface, which preserves its initial thickness providing protection to the underlying substrate. In general, only negligible changes of the phase composition of the coatings were noticed with simultaneous strengthening controlled in the micro-hardness measurements, even after 10-hours of heating at 1100 °C. On the other hand, the electrochemical corrosion tests, which were carried out in 200 ppm Cl − (NaCl) and pH ~4 (H2SO4) solution to simulate the acid-rain environment, reveal higher values of the breakdown potential for D-gun sprayed Fe-Al type coatings than the ones for the bulk Fe-Al type alloy and Cr21Mn9Ni4 austenitic valve steel. This enables these materials to be used in structural and multifunctional applications in aggressive environments, including acidic ones.

Archives of Metallurgy and Materials, 2018

The morphology of Fe-Al type intermetallic coatings produced by detonation spraying on a 045 stee... more The morphology of Fe-Al type intermetallic coatings produced by detonation spraying on a 045 steel substrate was described based on the microstructure analysis using transmission electron microscopy (TEM), and selected area electron diffraction (SAED) techniques as well as an analysis of chemical composition in microareas (EDS). The TEM was useful in establishing the coating structure in the vicinity of the interface between the substrate and the coating up to the depth of 10 m. Starting from the boundary with the substrate, an amorphous phase (A), then columnar crystals (CC) followed by crystalline grains of Fe3Al were observed. Farther on, the amorphous phase again and grains of the FeAl2 phase were localized. The Fe2Al5 and Fe3Al phases lay close to the coating surface. The phase transformations were completed with calorimetric analysis, which showed heat effects typical for magnetic transformations and ordering. The results indicated to the mechanism of coating formation which c...