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1

The fixed-effects analysis of the relation between SDAS and carbides for the airfoil blade traces

Pietraszek J., Szczotok A., Radek N.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

235--239

EN

The primary objective was to test a usefulness of the specific fixed-effect model for the analysis of quantitative relationships gathered from the image analysis of the material microstructures. The dataset was obtained from the investigation of turbine blades made from superalloy IN713C. The analysis based on the general linear model resulted in informative plots revealing mutual relationships between secondary dendrite arm spacing and the mean plane section area of carbides in the material. Directions for further research also were obtained.

2

Metallographic Study and Repeatability Analysis of γ' Phase Precipitates in Cored, Thin-Walled Castings Made from IN713C Superallo

Szczotok A., Pietraszek J., Radek N.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

595--601

EN

The study describes the influence of a surface modification in cored, thin-walled castings of blades from IN-713C nickel superalloy on γ' phase precipitates. The blades were produced by using the investment casting process in the laboratory conditions as parts for a low-pressure turbine rotor. The microstructural observations of the γ' phase precipitates on the cross sections of the blades were performed. The observations were followed by quantitative metallography evaluation, and finally, a comparison of the precipitates between one blade with the conventionally applied ceramic core and one with the core covered layer contained a surface modifier (5% of CoAl2O4) was made.

3

Influence of variable casting wall thickness and shell mold material and its thermal properties on secondary dendrite arm spacing in IN 713C superalloy castings

Szczotok A.

Inżynieria Materiałowa

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2016

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Vol. 37, nr 5

217--222

EN

The results of microstructure investigations of IN 713C superalloys obtained as thin walled‚ wedge’ castings from three kinds of shell molds are presented. Light microscopy, scanning electron microscopy observations and secondary dendrite arm spacing (SDAS) measurements were used to determine the differences in the IN 713C castings obtained using three kinds of shell mold materials. The effects of major constituents of the three shell molds: zirconium silicate ZrSiO4, aluminosilicate mAl2O3 . nSiO2 and SiC-based system on the SDAS in the investigated castings of the IN 713C superalloy are described. The results confirm that crystallization conditions (the variable wall thickness of the casting and material of the shell) of the IN 713C castings influence their microstructure. The increased SiC content in the shell molds has an effect on the crystallization process kinetics as indicated by the changes in the observed secondary dendrite arm spacing.

PL

Powszechnie wiadomo, że parametry procesu odlewania mogą wpływać na mikrostrukturę i właściwości mechaniczne nadstopów na osnowie niklu. Zmniejszenie odległości między ramionami wtórnymi dendrytów (SDAS) prowadzi do zredukowania porowatości i obszarów eutektyki w odlewie. Celem przeprowadzonych badań było ustalenie wpływu grubości ścianki odlewu oraz składu materiału i właściwości cieplnych formy ceramicznej na odległości między ramionami wtórnymi dendrytów w odlewach z nadstopu IN 713C.

4

Characterization of IN713C superalloy microstructure after high temperature creep test by LM, SEM and STEM

Szczotok A., Kościelniak B.

Inżynieria Materiałowa

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2016

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Vol. 37, nr 2

50--58

EN

This work focuses on the influence of creep phenomenon on the cast IN713C nickel-based superalloy. The carrot-shape IN713C superalloy castings were produced in an investment casting cluster mould and the creep test samples were then prepared from the castings. The creep tests were carried out in order to investigate processing–microstructure–property relationships. The resultant macro- and microstructures were observed and characterized after the creep tests using light microscopy, scanning electron microscopy and scanning transmission electron microscopy. The aim of the analysis was to reveal the changes in the microstructure that occurred as a result of the creep and to identify the phases that participate in voids formation, and crack generation and propagation during the creep tests. It was confirmed that the creep resistance of the IN713C superalloy is negatively affected by some structural characteristics such as porosity, (γ + γ′) eutectic or carbide precipitates along the grain boundaries. Our work confirms that a combination of thermal conditions with a tensile force affected the microstructure of IN713C nickel-based superalloy causing changes in morphologies of the existing precipitations and phase transformations, as in the case of the carbides. Additionally, carbide sulphides containing primarily Zr and intermetallic phase including mainly Ni and Zr were observed.

PL

Artykuł dotyczy wpływu zjawiska pełzania na strukturę odlewniczego nadstopu na osnowie niklu IN713C. Makro- i mikrostrukturę materiału uzyskaną w efekcie przeprowadzonej próby pełzania obserwowano przy różnych powiększeniach. Celem badań było ujawnienie zmian struktury, jakie pojawiły się w efekcie pełzania i zidentyfikowanie faz, które brały udział w powstawaniu nieciągłości materiału oraz generowaniu i propagacji pęknięć podczas próby pełzania.

5

Evaluation of Casting Shrinkage and Liquid Metal Fluidity of IN-713C Alloy

Binczyk F., Cieśla M., Gradoń P., Findziński A.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 1

9--12

EN

This paper presents the results of measurements of liquid metal fluidity and linear shrinkage of nickel alloy IN-713C in vacuum induction melting furnace Balzers VSG-2. Because of limited volume of the furnace chamber special models for technological trials were fluidity of hypoeutectic silumin, however in case of nickel superalloy the mould cavity was completely filled in each test because of high required pouring temperature. Positive results were obtained from the modified spiral test for all alloys used in the research. Relationship between the linear shrinkage for the test rod and a specific indicator of contraction defined on a spiral was observed.

6

Surface defects of investment castings of turbofan engine components made of IN713C nickel superalloy

Matysiak H., Michalski J., Balkowiec A., Sikorski K., Kurzydłowski K. J.

Materials Science Poland

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2009

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Vol. 27, No. 4/1

1103--1110

EN

The purpose of this study was to investigate typical casting defects occurring in investment cast turbofan engine parts made of IN713 C superalloy. SEM and EDS examinations were used to reveal that dross and non-metallic inclusions of a shell mould and crucible material are the most frequently occurring defects. A hypothesis is put forward with regard to the mechanisms of dross formation. EBSD studies were also carried out to reveal grain structure of the elements in question.