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Application of Quantitative Metallography to Cast Nickel-Based Superalloys

Agnieszka Szczotok, Jan Cwajna
2015 Microscopy and Microanalysis  
Quantitative stereology, or metallography, is concerned with the quantitative characterization of microstructures in terms of their point, lineal, areal, and volume elements. By means of suitable twodimensional measurements on the plane(s) of polish, statistically exact information can be obtained about the microstructural features in the three-dimensional space occupied by the alloy. These geometrical relationships have great generality and apply equally well to minerals, ceramics, plants, and
more » ... metals [1] . In other words, quantitative stereology is a good method for estimating 3D structures, quantifying them through the measurement and calculation of parameters of 2D structures (twodimensional sections). Stereology has had a great impact in astronomy, geology, metallurgy, biology, medicine and materials science since 1961 when International Society for Stereology was founded. The presented review is a result of many years of experience achieved during the research on production technologies and microstructures of cast nickel-based superalloys. The data presented in the work cases concerned investigations on microstructure of metallic materials employed in a hot section of the aircraft engines. Their microstructure provides the unusual properties making possible utilization at high temperatures and under load bearing conditions. The materials research were carried out according to the authors' proposed scheme of a complex procedure for quantitative description of the selected, investigated elements of the microstructure, e.g., grains, carbides, pores, etc. The suggested procedure consists of many steps. All of them are important and indispensable. Even their sequence can influence obtaining proper results. The experiences obtained showed that only by application of a complex research procedure, including every step of knowledge beginning with the technological history of the element, the research aims, sampling strategy, specimen preparation, through selection of observation method, image acquisition and analysis and finally determination of measurement errors and carrying out statistical analysis of the results, enables one to obtain precise, repeatable results. The examples presented were selected to review the studies performed and to emphasize the need to focus attention upon certain aspects of the research conducted; for example, sampling strategy and its affect on comparison of results, selection of the appropriate etchant and condition of etching to reveal the macro-and microstructure or the state of the material. The appropriate sampling strategy enables one to obtain information about diversification of microstructure in the whole cast element. Sometimes you can fail to obtain similar results conducting grain observation and their measurements on the surface of the turbine blade compare to on its cross-sections [2, 3] . In some cases, finding and applying the proper etchant for revealing microstructure of the superalloy is tedious. There are many known etchants used for superalloys, but not all are useful for microstructural investigations of a specific superalloy. The etchants which are good for light microscopy (LM) observation of the superalloy microstructure usually are completely useless for scanning electron microscopy (SEM) observations. On the other hand, if you are looking long enough you can match the etchant to the superalloy to obtain great effects with microstructure observations using SEM and LM. Some etchants seem to be appropriate for qualitative description rather than quantitative estimation of microstructure elements. Technological history of the cast element is very important for a quantitative estimation of specific structural elements. For example microstructure of nickel based superalloys highly depend on the heat treatment used. The γ' phase is the primary strengthening phase in nickel-based superalloys. The
doi:10.1017/s1431927615007485 fatcat:ssptib3ahbcthmahl34pdrvmdu

ICT development on the example of selected software applied in manufacturing area

Agnieszka Szczotok, Renata Dwornicka, R. Ulewicz, B. Hadzima
2018 MATEC Web of Conferences  
This paper provides an insight into a few selected aspects of computer-aided software usage in the manufacturing processes. This research aims to point out a diversity of software used in manufacturing area which is available on the market and to summarize most of the functionalities of three selected types of software for production zone backing.
doi:10.1051/matecconf/201818301010 fatcat:6arynwade5f4xozelzq4gj4tym

The Morphology and Mechanical Properties of ESD Coatings before and after Laser Beam Machining

Norbert Radek, Jacek Pietraszek, Aneta Gądek-Moszczak, Łukasz J. Orman, Agnieszka Szczotok
2020 Materials  
Electro-spark deposition (ESD) and laser beam machining (LBM) are the technologies using the concentrated energy flux. This paper deals with the issue of the impact of laser modification on the morphology and mechanical properties of carbide/copper coatings produced by electro-spark treatment. The coatings were applied to C45 carbon steel samples using the EIL-8A device. The following three types of electrodes made using the powder metallurgy (PM) hot pressing technique, from copper and
more » ... carbide powders of different percentage compositions, were used for the coatings: 25% WC and 75% Cu; 50% WC and 50% Cu; and 75% WC and 25% Cu. Laser modification of the surface layers was performed with an Nd:YAG laser. The research focused on the analysis of the morphology of coatings applied by electro-spark technology before and after laser processing. The analysis of the morphology of electro-spark coatings revealed that the coatings had microcracks and pores. The laser beam machining of ESD coatings led to the homogenization of chemical composition, fragmentation of the structure, and elimination of microcracks. In addition, measurements of porosity, microhardness, adhesion, and analysis of XRD phase composition of the electro-spark coatings were performed. Laser processing proved to have a positive effect on improving the adhesion of coatings and reducing their porosity. This paper also presents a simulation model of heat transfer processes for the case of laser radiation impact on a WC-Cu coating. The developed numerical model, describing the influence of laser treatment on the distribution of temperature fields in the heated material (at a given depth) is of significant importance in the development of treatment technologies. Laser-modified ESD coatings perform anti-wear and protective functions, which enable their potential application in means of transport such as rolling stock.
doi:10.3390/ma13102331 pmid:32438651 fatcat:5pw3jwzrdnelvpueoqi6r3s3va

The analysis of friction properties after laser texturizing of the silicon carbide surface layer

Norbert Radek, Agnieszka Szczotok, Renata Dwornicka, R. Ulewicz, B. Hadzima
2018 MATEC Web of Conferences  
The modification of the surface properties is a desired technological procedure. One of the possible method is the electro-spark deposition (ESD). Unfortunately, ESD process produces a surface with high roughness. The laser beam machining (LBM) has been involved to lower roughness of the coating made by ESD. The elements coated by ESD have been tested to determine tribological properties and they were compared before and after LBM. To achieve high reliability of the results, the test has been
more » ... nducted in accordance with design of experiments methodology and the results which were obtained have been processed by a statistical analysis. The description of such an experiment performed for a silicon carbide SiC coating, the obtained results and the conclusions are included in this paper.
doi:10.1051/matecconf/201818302010 fatcat:i7z4fqdydnc47fjcm2zsf567ju

Methodology for Revealing the Phases and Microstructural Constituents of the CMSX-4 Nickel-Based Superalloy Implicating Their Computer-Aided Detection for Image Analysis

Agnieszka Szczotok, Hannah Reichel
2020 Materials  
The paper presents the findings of a research on the selection of methodology for revealing the microstructure in metallographic investigations on the example of the single-crystalline CMSX-4 nickel-based superalloy. A set of chemical and electrochemical methods of etching has been selected. The metallographic specimens from the analyzed material have been treated with the etchants. After every etching procedure, microphotographs of the microstructure were taken by means of an optical
more » ... and a scanning electron microscope. Both useful and disadvantageous effects of etching with the respective etchants have been displayed. The etchant application for a qualitative and quantitative analysis has been considered on the basis of the enclosed microphotographs. As a result, examples of a computer-aided detection of the phases and microstructural constituents present in the analyzed CMSX-4 alloy for the selected revealing methodologies have been demonstrated. The described investigations enable a better understanding of the essence of the selection of the microstructure revealing methodology and its influence on the obtained results.
doi:10.3390/ma13020341 pmid:31940800 pmcid:PMC7014115 fatcat:fqmcn5dqhbfqxjnt63onndduda

An Improved Procedure for the Quality Control of Sintered Carbide Tips for Mining Applications, Based on Quantitative Image Analysis of the Microstructure

Kamil Mucha, Joanna Augustyn-Nadzieja, Agnieszka Szczotok, Krzysztof Krauze
2021 Materials  
Conical picks are tools that treat surfaces used in mining. Due to a wide variety of such tools, they need to characterise in diversified geometrical and material parameters, as well as durability. For the mining sector, evaluation of the conical picks is performed in order to verify their agreement with the manufacturer's declaration, as well as with the requirements of the user. One of the whole research procedure elements is a qualitative and quantitative analysis of a pick tip made of
more » ... ed carbide (tungsten carbide–cobalt; WC-Co). It is currently carried out when the recipient is accepting such picks or when a complaint is made. In this case, it is important to propose such a research and control procedure that will make it possible to determine the quality of the applied material for pick tips in a straightforward, repeatable, and objective way. This article presents the results of investigations made on tips coming from four different types of conical picks. The tips' hardness and density were measured, as well as WC grains which were characterised using two kinds of measurements (automated linear-intercept method and semi-automated planimetric methods). The measurements of the WC grains were conducted on microstructure images recorded using a light microscope. The performed investigations made it possible to compare tips and refer the results to those of other scientists' studies. The final effect is a proposal of a specialised procedure examining picks, especially their tips, made of sintered carbides. This is important for the evaluation of the tips' quality in light of the requirements of the relevant norms and the needs of the users from the mining and extractive sectors.
doi:10.3390/ma14051236 pmid:33807921 fatcat:bwinavrhebehzpypqmjfqjpu3q

Assessment of mechanical strength and corrosion resistance at variable pH of orthodontic wires

Joanna Augustyn-Nadzieja, Agnieszka Szczotok
2020
Orthodontic wires are components of fixed appliances used to perform the necessary tooth movements in the course of the orthodontic treatment. A variety of materials e.g. metals, alloys, polymers and composites are used to produce orthodontic wires. This study examined the mechanical strength and cracks resistance of three different types of wires, i.e. made of: austenitic steel grade AISI 303, NiTi alloy and Tiβ alloy. Corrosion processes are regarded to have a harmful effect on the properties
more » ... of orthodontic wires, such as their strength, biocompatibility and aesthetic appearance. In this study, we investigated the corrosive behaviour of the wires in the artificial saliva solutions with varied pH simulating the natural oral cavity environment. It was demonstrated that the orthodontic rectangular wires made of austenitic steel grade AISI 303 exhibited the highest tensile strength. The NiTi alloy wires exhibited the best plastic properties of all the examined samples. In the case of electrochemical tests (changes in corrosion potential over a period of 24 h), the wire made of austenitic steel and the NiTi alloy wire reached a stable level of the stationary potential in the acidic environment. For the wires made of Tiβ, the highest stationary potential was observed in the alkaline environment. Additionally, the Tiβ alloy wire revealed the broadest passivation area in the specified potential scope.
doi:10.34821/eng.biomat.157.2020.2-9 fatcat:itudc53nebcyjesfopkgvp52xe

Can You Identify the Microstructure?

2012 Metallography Microstructure and Analysis  
The first person to send in a correct answer was Agnieszka Szczotok, Ph.D., Silesian University of Technology, Faculty of Materials Engineering and Metallurgy, Katowice, Poland.  ... 
doi:10.1007/s13632-012-0022-z fatcat:rewqfc2ksbgktnkzqi5zgr7l4e

The influence of prosthetic elements manufacturing technology on properties and microstructure shaping Co-Cr-Mo alloys

Joanna Augustyn-Nadzieja, Agnieszka Szczotok
2020
The presented publication discusses the test results regarding samples of a prosthetic alloy from the Co-Cr- Mo system. The test samples were obtained by means of two different methods applied in prosthetics laboratories to compare their properties and microstructure. To obtain the samples via the traditional lost wax casting method, the cast alloy Co-Cr-Mo was used, commercially known as Wironit LA. In the case of the modern technique DMLS (Direct Metal Laser Sintering), metallic powder
more » ... o, called EOS Cobalt Chrome MP1, was used. The samples of both Co-Cr-Mo alloys obtained via the two methods were prepared for metallographic tests; they also underwent microstructural observations with the use of light microscopy (LM) and scanning electron microscopy (SEM), and next they were subjected to hardness tests. The obtained samples demonstrated a dendritic structure. In the samples cast with the lost wax casting method, a segregation of the chemical composition was revealed. The samples obtained by means of the DLMS method were characterized by chemical composition homogeneity. The hardness measurements with the statistical analysis of the measurement results showed a difference between the examined alloys. On the basis of the performed studies, it was stated that the applied methods of manufacturing prosthetic elements make it possible to obtain diversified microstructural and mechanical properties of the alloys. The hardness value significantly affects the subsequent mechanical and finishing treatment of prosthetic elements, such as metal bases of crown caps, bridges, mobile prostheses or other retention elements. Keywords: Co-Cr-Mo alloys, dental prosthetics, lost wax casting method, selective laser sintering of metal powders (DLMS), microstructure, hardness [Engineering of Biomaterials 156 (2020) 24-31]
doi:10.34821/eng.biomat.156.2020.24-31 fatcat:e4x7obrowvfl7n4diaabozs2yu

application of two NON-COMMERCIAL PROGRAMMES TO image processing and extraction of selected features occurring in MATERIAL MICROSTRUCTURE

Agnieszka SZCZOTOK, Dariusz KARPISZ
2019 METAL 2019 Conference Proeedings   unpublished
doi:10.37904/metal.2019.971 fatcat:anv7i7qrpvfkle4uoewvf3thxm

THE BOOTSTRAP APPROACH TO THE STATISTICAL SIGNIFICANCE OF PARAMETERS IN THE FIXED EFFECTS MODEL

Jacek Pietraszek, Renata Dwornicka, Agnieszka Szczotok
2016 Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016)   unpublished
The description below is a brief, while details can be found in article of Szczotok et al. [11] . Nickel-based superalloys are mainly used in aircraft and power-generation turbines.  ... 
doi:10.7712/100016.2240.9206 fatcat:3ietjelsvjaxdlvtv32d4gu2te

Acknowledgement to Reviewers of Metals in 2019

Metals Editorial Office
2020 Metals  
, Agnieszka Szczucka-Lasota, Bożena Szewczyk, Roman Szielasko, Klaus Szkliniarz, Agnieszka Szkodo, Marek Szmytka, Fabien Szwajka, Krzysztof SZYBIŃSKI, BOGDAN Szymczak, Tomasz Tabelin, Carlito  ...  Johannes Albert Osuch, Piotr Owolabi, Gbadebo Ozerov, Maxim Păcurar, Razvan Pagan, Darren Ranzi, Eliseo Svoboda, Jiri Swiatkowska, Zaneta Świercz, Rafał Świerczyńska, Aleksandra Szala, Miroslaw Szczotok  ... 
doi:10.3390/met10010150 fatcat:awtgpm4mr5buzavwdglwd3quby

Teologiczne Studia Siedleckie XI (2014)

Ks. Kazimierz MATWIEJUK, Ks. Piotr MAZUREK, Ks. Roman KRAWCZYK, Ks. Ireneusz CELARY, Ks. Zbigniew SOBOLEWSKI, Ks. Dariusz KRUCZYŃSKI, Ks. Rafał WIERZCHANOWSKI, Ks. Marcin Piotr BIDER, Ks. Robert MIROŃCZUK, Ks. Łukasz SZCZEBLEWSKI, Ks. Jacek WOJDA, Ks. Łukasz GOMÓŁKA (+2 others)
2021 Zenodo  
Szczotok, A. Liskowacka, Katowice 1994, s. 158; zob. A.  ...  Szczotok, A. Liskowacka, Katowice 1994, s. 9-10; zob. A.  ... 
doi:10.5281/zenodo.5565206 fatcat:btkvvuc6yzbbrj2wlphkz4xe4a