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1

Assessment of the feasibility of determining the volume fraction and characteristics of the size, shape and distribution of γ’ phase precipitates in nickel-based superalloys

Szczotok Agnieszka

Technical Transactions

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2023

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Vol. 120, iss. 1

art. no. e2023011

EN

This overview presents a comprehensive exploration of the research methodsemployed for the precise assessment of volume fraction and the detailedcharacterisation of the size, shape and distribution of γ' phase precipitates withinNi-based superalloys. These advanced materials exhibit exceptional mechanicalproperties due to the presence of γ' precipitates. The accurate quantification ofprecipitate parameters is crucial for understanding material behaviour and forthe optimisation of alloy design. In this overview, a spectrum of techniques,including microscopy (SEM, TEM), diffraction (XRD), spectroscopy (EDS, EELS)and advanced imaging (3D-APT, STEM-HAADF, FIB-SEM) is discussed. Strengths,limitations and potential synergies among these methods are highlighted, offeringresearchers a comprehensive toolbox to advance their investigations of γ' phaseprecipitates in Ni-based superalloys.

2

Regeneracja warstw aluminidkowych na podłożu nadstopów niklu stosowanych na łopatki silników lotniczych

Kwolek Przemysław, Góral Marek, Poznańska Anna, Wierzbińska Małgorzata, Ochał Kamil

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2019

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z. 91 [299], nr 1-2

53--65

PL

W artykule przedstawiono wybrane metody usuwania dyfuzyjnych warstw aluminidkowych stosowanych do ochrony powierzchni łopatek turbin silników lotniczych przed oddziaływaniem korozji wysokotemperaturowej. Scharakteryzowano opracowane dotychczas chemiczne i elektrochemiczne metody rozpuszczania warstw aluminidkowych. Na podstawie analizy danych literaturowych wytypowano 3 roztwory: kwasu siarkowego(VI) o stężeniu 25% mas., mieszaninę stężonego kwasu solnego (40% obj.) i etanolu (60% obj.) oraz mieszaninę stężonych kwasów ortofosforowego (50% obj.), octowego (25% obj.), azotowego (25% obj.). Przeprowadzono badania kinetyki rozpuszczania modelowej warstwy aluminidkowej modyfikowanej cyrkonem na podłożu stopu Inconel 100. Wykazano, że niezależnie od zastosowanych roztworów, rozpuszczanie następuje równomiernie na powierzchni warstwy. Stwierdzono, że największą skutecznością w usuwaniu warstw cechowała się mieszanina kwasów: ortofosforowego, octowego i azotowego, w której rozpuszczenie warstwy aluminidkowej następowało po ok. 80 min.

EN

Selected methods of removing diffusion alluminide coating used for protection of turbine blades were presented in the article. The chemical and electrochemical methods of coatings dissolution used in aerospace industry were described. Three selected removing agents were selected for experimental tests: hydrochloric acid in ethanol solution, sulphuric acid in water as well as mixture of orthophosphoric, acetic and nitride acids. The aluminide coating obtained on IN-100 nickel superalloy was used for tests. The conducted research showed that the mixture of orthophosphoric, acetic and nitride acids can dissolve outer-zone of aluminidce coating during 80 min dissolution process. The removing process takes place evenly on the whole surface of sample.

3

Influence of hafnium on high temperature oxidation of NiAl and Ni3Al alloys

Swadźba R.

Prace Instytutu Metalurgii Żelaza

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2018

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T. 70, nr 2

19--29

EN

The results presented in this paper concern the modification of NiAl and Ni3Al alloys with reactive elements that increase their high temperature oxidation resistance. Literature data indicate that even trace additions of Hf to aluminide coatings significantly improve the resistance to oxidation in the range of 1100-1150°C, however the exact mechanism of its influence is not yet known. In order to determine the influence of various additions of Hf on high temperature oxidation of aluminide coatings, cyclic oxidation tests were performed at 1150°C of model NiAl and Ni3Al alloys with different Hf additions - from 0.25 wt.% to 1.5 wt.%. High resolution electron microscopy, as well as chemical composition analysis techniques, were applied to perform a detailed characterisation of the influence of Hf on the substructure, chemical and phase composition in the nano scale of oxide scales formed during high temperature oxidation.

PL

Wyniki przedstawione w artykule dotyczą modyfikacji tzw. pierwiastkami reaktywnymi faz wchodzących w skład dyfuzyjnych powłok aluminidkowych stosowanych na łopatki turbin silników lotniczych w celu zwiększenia ich odporności na utlenianie wysokotemperaturowe. Dane literaturowe wskazują, że nawet niewielki dodatek Hf w powłokach aluminidkowych bardzo silnie wpływa na wzrost odporności na utlenianie w zakresie temperatury 1100÷1150°C, jednak dokładny mechanizm jego wpływu nie jest do końca poznany. W celu określenia wpływu różnej zawartości Hf oraz scharakteryzowania mechanizmu jego oddziaływania na procesy utleniania wysokotemperaturowego powłok aluminidkowych przeprowadzono badania cyklicznego utleniania w temperaturze 1150°C stopów modelowych NiAl i Ni3Al o różnej zawartości Hf - od 0,05% mas. do 1,5% mas. Do przeprowadzenia szczegółowej analizy wpływu Hf na substrukturę, skład chemiczny oraz fazowy w skali nano warstw tlenkowych powstających podczas utleniania wysokotemperaturowego wykorzystano techniki wysokorozdzielczej mikroskopii elektronowej oraz analizy składu chemicznego.

4

Contribution of Microstructural Constituents on Hot Cracking of MAR-M247 Nickel Based Superalloy

Rakoczy Ł., Grudzień M., Zielińska-Lipiec A.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

181--189

EN

The aim of this study is to investigate influence of selected parameters of gas tungsten arc welding on microstructure of MAR-M247 nickel based superalloy originating from turbine vane. MAR-M247 is a precipitation-strengthened superalloy which is widely used in aerospace engines. The main strengthening phase in this material is ordered L12 intermetallic γ' phase Ni3 (Al, Ti). The surface of alloy was modified by electric arc in order to present microstructural changes in weld and heat affected zone. Investigation of the heat affected zone revealed that constitutional liquation of γ' particles and primary carbides is responsible for the formation of a liquid grain boundary layer which finally contributed to cracking. Scanning electron microscopy indicated high susceptibility to cracking of MAR-M247 alloy which is connected with high content of γ'-formers aluminum and titanium.

5

Analiza mikrostrukturalna i charakterystyka pęknięć po spawaniu łukowym nadstopu niklu

Rakoczy Ł., Zielińska-Lipiec A., Tuz L., Pańcikiewicz K.

Hutnik, Wiadomości Hutnicze

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2017

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Vol. 84, nr 4

156--161

PL

W artykule przedstawiono badania za pomocą mikroskopu świetlnego i skaningowego mikrostruktury odlewniczego stopu niklu umacnianego wydzieleniowo fazą międzymetaliczną Ni3(Al,Ti) po spawaniu metodą GTAW. Ujawniono, iż w rdzeniach dendrytów występują głównie pierwotne i wtórne wydzielenia fazy γ’ w osnowie γ, natomiast w obszarach międzydendrytycznych obserwowano eutektykę γ/γ’ oraz węgliki typu MC. Stosunkowo duże różnice mikrostruktury w tych dwóch charakterystycznych obszarach materiału rodzimego świadczą o dużej lokalnej niejednorodności. Podczas obserwacji za pomocą SEM po spawaniu zauważono mikropęknięcia gorące w strefie wpływu ciepła (SWC). Stwierdzono, że ciecz w SWC podczas spawania pojawia się w wyniku nierównowagowego nadtapiania fazy umacniającej γ’. Analiza przełomu autogenicznego połączenia ujawniła w materiale rodzimym złożony charakter pęknięcia. Kruchy charakter pęknięcia obserwowano na wydzieleniach fazy γ’, eutektyki γ/γ’ i węglików, natomiast ciągliwy w osnowie γ. W strefie wpływu ciepła ujawniono pęknięcie likwacyjne o charakterystycznej powierzchni swobodnej.

EN

Paper presents microstructural investigation using light and scanning electron microscopy of cast nickel based superalloy with trade name Rene 108 after Gas Tungsten Arc Welding. Analysis of base metal revealed that inside dendrite cores are mainly primary and secondary γ› precipitations, while constituents in interdendritic spaces are eutectic γ/γ› and MC-type carbides. Substantial differences in those two regions indicate on relatively high local inhomogeneities. SEM investigation showed microfissuring in heat affected zone. It was found that during welding liquid was created in HAZ via constitutional liquation of intermetallic γ› phase. SEM analysis of fracture revealed brittle failure of γ› phase, eutectic islands γ/γ› and MC-type carbides, in turn plastic deformation of γ-matrix. In heat affected zone the free surface of liquation crack was observed.

6

Nd-YAG Laser Beam-Induced Liquation Cracking in Selected Nickel-Based Superalloys

Rakoczy Ł., Zielińska-Lipiec A., Tuz L., Góral T.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2017

|

Vol. 61, No. 1

32--38

EN

MAR-M247 and Rene 77 belong to intermetallic phase Ni₃(Al, Ti) precipitation hardened nickel alloys widely used in the aerospace and power engineering industries. Because of their susceptibility to cracking, the above-named alloys are characterised by limited weldability. In the tests described in this article, the surfaces of the above-named superalloys were affected by a laser beam having identical parameters. Afterwards, the test results concerning the individual susceptibility to Nd-YAG laser beam-induced liquation cracking were compared. The stereoscopic microscopic observations revealed differences indicating the significantly greater crack susceptibility of superalloy MAR-M247. The characteristics of the materials indicated that the above differences were connected with the significantly more complex microstructure resulting from the segregation of alloying elements during crystallisation. The scanning microscopic examination revealed the presence of liquation cracks in the HAZ located along partially melted interdendritic areas.

PL

Stopy MAR-M247 oraz Rene 77 należą do grupy stopów niklu umacnianych wydzieleniowo fazą międzymetaliczną Ni3(Al, Ti) znajdujących szerokie zastosowanie w branży lotniczej i energetycznej. Uważane są za stopy o ograniczonej spawalności z powodu wysokiej skłonności do pękania. W omawianej pracy powierzchnię tych nadstopów poddano oddziaływaniu wiązki laserowej przy zastosowaniu identycznych parametrów. Na podstawie przeprowadzonych badań porównano skłonność stopów do pęknięć likwacyjnych powstałych w wyniku oddziaływania wiązki laserowej Nd-YAG. Obserwacja powierzchni za pomocą mikroskopu stereoskopowego ujawniła różnice wskazujące na dużo wyższą skłonność do pękania nadstopu MAR-M247. Charakterystyka materiałów wskazała, iż jest to związane ze znacznie bardziej złożoną mikrostrukturą wynikającą z segregacji składników stopowych w trakcie krystalizacji. Badania przy pomocy mikroskopii skaningowej ujawniły pęknięcia likwacyjne w SWC biegnące wzdłuż nadtopionych obszarów międzydendrytycznych.

7

Quantitative Evaluation of Porosity in Turbine Blades Made of IN713C Superalloy After Hot Isostatic Pressing

Roskosz S.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

253--258

EN

The aim of this paper is an assessment of the influence of hot isostatic pressing treatment on porosity of cast samples - turbine blades and vane clusters made of the IN713C superalloy. Two variants of HIP treatments, differing in pressure from each other, have been used. The quantitative evaluation of the porosity was performed using light microscopy and quantitative metallography methods. The use of the hot isostatic pressing significantly decreased the volume fraction and size of pores in the test blades, the remaining pores after the HIP process being characterized by a round shape. The increased pressure has caused significant reductions in the area fraction and size of the pores.

8

Effect of hot isostatic pressing on the microstructure of turbine blade airfoil made of nickel-base superalloy

Chmiela B., Kościelniak B., Cwajna J.

Archives of Metallurgy and Materials

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2017

|

Vol. 62, iss. 1

241--245

EN

Turbine blades are flight safety parts in the jet engine. Therefore they should be characterized by very good mechanical properties, especially high creep resistance and fatigue strength at high temperature. The mechanical properties of blades made of nickel-based superalloys depend on the microstructure of the casting and its porosity [1,2]. The aim of this paper is evaluation of effect of hot isostatic pressing (HIP) on microstructure of blade airfoil made of IN713C superalloy in four important zones: (i) leading edge, (ii) trailing edge, (iii) suction side and (iv) pressure side. HIP treatment was carried out proving some significant microstructural changes. Electron backscatter diffraction (EBSD) analysis reveals some structural changes what may facilitate diffusion processes leading to simplify of a heat treatment (solution treatment and aging).

9

Numerical Simulation of Directional Solidification Process of Single Crystal Ni- Based Superalloy Casting

Szeliga D., Kubiak K., Sieniawski J.

Archives of Foundry Engineering

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2017

|

Vol. 17, iss. 2

111--118

EN

The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould (3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5 and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

10

Microstructure and Properties of a Repair Weld in a Nickel Based Superalloy Gas Turbine Component

Rakoczy Ł., Grudzień M., Tuz L., Pańcikiewicz K., Zielińska-Lipiec A.

Advances in Materials Science

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2017

|

Vol. 17, nr 2(52)

57--63

EN

The aim of the present study was to characterize the repair weld of serviced (aged) solid-solution Ni-Cr-Fe-Mo alloy: Hastelloy X. The repair welding of a gas turbine part was carried out using Gas Tungsten Arc Welding (GTAW), the same process as for new parts. Light microscopy, scanning electron microscopy, transmission electron microscopy, microhardness measurements were the techniques used to determine the post repair condition of the alloy. Compared to the solution state, an increased amount of M6C carbide was detected, but M23C6 carbides, sigma and mu phases were not. The aged condition corresponds to higher hardness, but without brittle regions that could initiate cracking.

11

Investment casting parameters impact on IN 713C nickel-based superalloy microstructure

Roskosz S., Cygan R.

Inżynieria Materiałowa

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2016

|

Vol. 37, nr 2

59--64

EN

The basic process for manufacturing of aircraft engine hot section elements made of nickel-based superalloys is investment casting using multilayer ceramic shell moulds. Introduction of new engines designs with higher thrust, lower fuel consumption and lower noise emissions enforce continual modification of casting materials, models, ceramic moulds, including melting, pouring and heat treatment processes parameters. The aim of this study was to determine the effect of pouring temperature and cobalt aluminate modifier in the subsurface layer of the mould on macrostructure of the IN 713C castings. The size of misruns, chill, columnar and equiaxed zones on the surface of the wedge castings is most affected by pouring temperature. Additionally it was proved that cobalt aluminate is an effective modifier of the IN713C superalloy causing not only refinement of equiaxed grains, but also reduction in the columnar grain size fraction.

PL

Nadstop niklu IN 713C jest stosowany między innymi na łopatki turbin silników lotniczych, odlewane precyzyjnie metodą traconego wosku w wielowarstwowych formach ceramicznych. Łopatki turbin często charakteryzują się gruboziarnistą i niejednorodną strukturą, która nie spełnia rygorystycznych wymagań dotyczących części wykorzystywanych w przemyśle lotniczym. Poprawę struktury łopatek wytworzonych z nadstopów niklu można uzyskać w wyniku odpowiedniego kształtowania wielkości ziarna w procesie odlewania. Ziarna o kontrolowanych rozmiarach można otrzymać dzięki odpowiedniej temperaturze zalewania, temperaturze formy i zastosowaniu modyfikatora w powierzchniowej warstwie formy odlewniczej. Celem badań było określenie wpływu temperatury zalewania oraz udziału modyfikatora CoAl2O4 w warstwie przypowierzchniowej formy odlewniczej na strukturę odlewów z nadstopu IN 713C.

12

Hot cracking of nickel-based superalloy turbine blade

Rakoczy Ł., Tuz L., Pańcikiewicz K.

Metallurgy and Foundry Engineering

|

2015

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Vol. 41, no. 4

181--188

EN

The aim of this study was to present the hot cracking behavior of a blade originating from a turbine blade segment. The crack was induced by a gas tungsten arc welding process, and the research material was a MAR-M247 nickel based superalloy. This alloy is considered to be difficult to weld because of its high tendency to crack. Light microscopy and scanning electron microscopy show the occurrence of cracking in the melted zone, heat-affected zone, and base alloy. A scanning electron microscopy investigation revealed that cracks are propagated by stresses and liquation of the low temperature constituent.

PL

Celem pracy była analiza mikrostrukturalna pęknięcia gorącego na powierzchni łopatki z segmentu van cluster. Pęknięcie powstało w wyniku oddziaływania skoncentrowanego źródła ciepła, jakim był łuk elektryczny jarzący się w osłonie argonu. Łopatka została wykonana z nadstopu na osnowie niklu o nazwie handlowej MAR-M247. W przypadku konwencjonalnych metod spawania jest on uważany za trudno spawalny. Przeprowadzono badania makrostruktury i mikrostruktury za pomocą mikroskopii świetlnej i skaningowej. Na podstawie wykonanych badań stwierdzono występowanie pęknięć ciągłych zarówno w obszarze przetopionym, strefie wpływu ciepła, jak i materiale rodzimym. Obserwacje za pomocą skaningowej mikroskopii elektronowej pozwoliły na stwierdzenie, że pęknięcie propagowało w wyniku naprężeń, jak również likwacji niskotopliwych składników mikrostruktury.

13

The selected properties of fusion of Fe foam and sheet metal with use of the Nd:YAG laser

Młynarczyk P., Depczyński W.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

|

Vol. 65, nr 2

68--72

EN

Purpose: In the paper there were presented possibilities of combining metal sheet with metallic foams using a Nd:YAG laser. Design/methodology/approach: The research were carried out over the properties of laser welded joint of micro-welds iron foam with superalloy HYNESH230®. Findings: The results indicated that there is a possibility of obtaining the satisfying quality joint between the Fe foam and superalloy Hynes H230®. Research limitations/implications: The studies mainly focused on the microstructural and some mechanical properties. Example of structural applications for metallic foams, utilizing benefits in weight, stiffness, energy dissipation, mechanical damping, and vibration frequency were summarized already by many authors. The authors chose to study selected properties of fusion of Fe foam and sheet metal with new approach. Originality/value: The studies used to determine basic quality parameters of the welded joint. Using EDS analysis, there were identified a types of alloying elements and the extent of diffusion from superalloy H 230® in the course of Fe foam. Also, there was investigated shear strength of obtained micro-welds.

14

Solid particle erosion behavior of Inconel 718 super alloys under elevated temperatures

Bircan B., Fidan S., Çimenoğlu H.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

|

Vol. 66, nr 1

5--12

EN

Purpose: This work deals with solid particle erosion behavior of Inconel 718 at elevated temperatures. Design/methodology/approach: Samples with 3 mm thickness, 25 mm diameter were tested at 3 different temperatures (20°C, 400°C and 600°C); at 4 impingement angles (30°, 45°, 60°, 90°) in a specially designed erosion test rig by using 120 mesh (90-125 μm) Al2O3 abrasive particles. Solid particle erosion damage characterization was achieved by evaluating the erosion rates after tests. Damage mechanisms were discussed by using scanning electron microscope (SEM) analysis. Surface topographies were analyzed in order to evaluate the effects of experimental parameters on solid particle erosion. Findings: Although the conclusion of this work is crucial for understanding the solid particle erosion behavior of Inconel 718 alloy used in turbine blades of aircraft gas turbine engines. Practical implications: This work may contribute to develop next generation alloys to be utilized in manufacturing of compressor blades exhibiting longer service durations. Originality/value: More detailed study about erosive wear performance of Inconel 718 as an aviation engineering material is crucial for future work.

15

Evaluation of High-temperature Physicochemical Interactions Between the H282Alloy Melt and Ceramic Material of the Crucible

Pirowski Z.

Archives of Foundry Engineering

|

2014

|

Vol. 14, iss. 4

83--90

EN

Nickel alloys belong to the group of most resistant materials when used under the extreme operating conditions, including chemically aggressive environment, high temperature, and high loads applied over a long period of time. Although in the global technology market one can find several standard cast nickel alloys, the vast majority of components operating in machines and equipment are made from alloys processed by the costly metalworking operations. Analysis of the available literature and own studies have shown that the use of casting technology in the manufacture of components from nickel alloys poses a lot of difficulty. This is due to the adverse technological properties of these alloys, like poor fluidity, high casting shrinkage, and above all, high reactivity of liquid metal with the atmospheric air over the bath and with the ceramic material of both the crucible and foundry mold. The scale of these problems increases with the expected growth of performance properties which these alloys should offer to the user. This article presents the results of studies of physico-chemical interactions that occur between the H282 alloy melt and selected refractory ceramic materials commonly used in foundry. Own methodology for conducting micro-melts on a laboratory scale was elaborated and discussed. The results obtained have revealed that the alumina-based ceramic sexhibits greater reactivity in contact with the H282 alloy melt than the materials based on zirconium ompounds. In the conducted experiments, the ceramic materials based on zirconium silicate have proved to be a much better choice than the zirconia-silica mixture. Regardless of the type of the ceramic materials used, the time and temperature of their contact with the nickel alloy melt should always be limited to an absolutely necessary minimum required by the technological regime.

16

Stress-strain curves under compression for CMSX4 nickel based superalloy

Nowotnik A., Pędrak P., Rokicki P., Mrówka-Nowotnik G., Sieniawski J.

Advances in Manufacturing Science and Technology

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2014

|

Vol. 38, nr 3

65--77

EN

Variations of a flow stress vs. true strain illustrate behavior of material during plastic deformation. Stress-strain relationship is generally evaluated by a torsion, compression and tensile tests. Results of these tests provide crucial information pertaining to the stress values which are necessary to run deformation process at specified deformation parameters. Uniaxial compression tests at the temperature through which precipitation hardening phases process occurred (900-1200°C), were conducted on superalloy - CMSX-4, to study the effect of temperature and strain rate (ε =10 to the -4 and 4x10 to the -4 s to the -1) on its flow stress. On the basis of received flow stress values activation energy of a high-temperature deformation process was estimated. Mathematical dependences (σpl - τ i σpl - ε) and compression data were used to determine material's constants. These constants allow to derive a formula that describes the relationship between strain rate (ε), deformation temperature (τ) and flow stress σpl - ε = A1σ to the n ∙ exp(-Q / RT).

PL

Zachowanie się materiału podczas odkształcania plastycznego na gorąco charakteryzują krzywe zmiany naprężenia uplastyczniającego w funkcji odkształcenia. Do ich oceny stosowane są próby skręcania, ściskania lub rozciągania. Pozwalają określić dane niezbędne do prowadzenia procesu przeróbki plastycznej materiału z zastosowaniem odpowiednich parametrów odkształcania - temperatury i prędkości chłodzenia. W pracy przedstawiono analizę wyników badań wpływu temperatury i prędkości odkształcania (ε = 10 do - 4 i 4 x 10 do -4 s do -1) na wartość naprężenia uplastyczniającego nadstopu niklu - CMSX-4 w zakresie wartości temperatury wydzielania cząstek faz umacniających (900-1200°C) uzyskane w jednoosiowej próbie ściskania. Ustalone wartości naprężenia uplastyczniającego były podstawą do wyznaczenia energii aktywacji Q procesu odkształcania wysokotemperaturowego. Na podstawie uzyskanych danych oraz odpowiednich zależności (σpl - τ i σpl - ε) określono wartości stałych materiałowych oraz ustalono zależność prędkości (ε), temperatury odkształcenia (τ) i naprężeniem ustalonego płynięcia plastycznego σpl - ε = A1σ do n ∙ exp(-Q / RT).

17

Computer decision support system structure for machining data selection in turning

Słodki B.

Advances in Manufacturing Science and Technology

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2013

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Vol. 37, nr 2

23--31

EN

The paper presents the structure of a complex system for supporting a decision making process in machining data selection in turning operations. It is assumed, that the system modules cooperate with each other, utilize data and knowledge bases through the information bus. The system proposes to use on line information from visual monitoring module equipped with high speed camera what enables to observe chip forms. Particular modules and their tasks in the system are described as well as some examples are described.

PL

W pracy przedstawiono strukturę systemu wspomagania decyzji w doborze parametrów skrawania dla toczenia. Budowa systemu zakłada współdziałanie wielu modułów – stosowanie baz danych i wiedzy połączonych magistralą informacyjną. System wykorzystuje informację z modułu monitorowania procesu skrawania wyposażonego w kamerę szybkoklatkową umożliwiające obserwację postaci i kształtu powstającego wióra. Przedstawiono zadania poszczególnych modułów systemu i przykłady ich działania.

18

Simultaneous monitoring of dynamic processes in the cutting zone in turning of superalloys by using thermovision and high-speed scanning

Šajgalík M, Pilc J, Borovsky R, Svitana M

Mechanik

|

2012

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R. 85, nr 8-9CD (SOS)

257--264

19

Mechanical properties of hot deformed Inconel 718 and X750

Nowotnik A., Pędrak P., Sieniawski J., Góral M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2012

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Vol. 50, nr 2

74--80

EN

Purpose: Variations of a flow stress vs. true strain illustrate behavior of material during plastic deformation. Stress-strain relationship is generally evaluated by a torsion, compression and tensile tests. Design/methodology/approach: Compression tests were carried out on precipitations hardenable nickel based superalloys of Inconel 718 and X750 at constant true strain rates of 10-4, 4x10-4, s-1, within temperature through which precipitation hardening phases process occurred (720-1150°C) using thermomechanical simulator Gleeble and dilatometer Baehr 850D/L equipped with compression unit. True stress-true strain curves analysis of hot deformed alloys were described. Findings: On the basis of received flow stress values activation energy of a high-temperature deformation process was estimated. Mathematical dependences (σpl -T i σpl - ε) and compression data were used to determine material’s constants. These constants allow to derive a formula that describes the relationship between strain rate (e), deformation temperature (T) and flow stress σpl. Research limitations/implications Study the flow stress will be continued on the samples after the aging process. Practical implications: The results of high-temperature deformation of the examined Inconel alloys may possibly find some practical use in the workshop practice to predict a flow stress values, but only within particular temperature and strain rate ranges. The results of the study can be used in the aerospace industry to produce blades for jet engines. Originality/value: The results of the study can be used in the aerospace industry to produce blades for jet engines.

20

Heat treatment and CVD aluminizing of Ni-base René 80 superalloy

Pytel M., Góral M., Nowotnik A., Sieniawski J., Drajewicz M., Ziaja W.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 51, nr 1

30--38

EN

Purpose: This work presents the results of microstructure investigations which were carried out on Ni-base Rene 80 polycrystalline superalloy. Design/methodology/approach: Polycrystalline cast rods have been used in the studies. The heat treatment processes were conducted in ALD High Temperature Vacuum Furnace at 1204°C for 2 h, in Ar atmosphere followed by cooling to room temperature. The aluminizing processes were conducted by use of CVD method on as cast samples and after homogenizing-solution annealing. The diffusion low activity aluminide coatings have been produced using the CVD IonBond BPXPR0325S apparatus at various temperatures, for 4 h and applying different values of: flow rate of HCl through the outer AlCl3 generator and pressure in main retort in H2 atmosphere. The microstructure investigations were conducted using scanning electron microscope. To the purpose of analysis of the chemical composition an X-ray microanalysis technique was applied with the dispersion of the energy (EDS) using of Thermo and Noran equipment. Findings: It was found that samples without heat treatment had the typical cast microstructure with many areas of the y-y’ eutectic, after heat treatment process the microstructure was homogenized, i.e. the eutectic y-y’ has been dissolved, MC-type carbides were precipitated on the grain boundaries and the chemical composition was balanced. It was found also that after homogenizing heat treatment the samples had the thicker coating and had more homogenous additive and diffusion layer than the samples with as-cast microstructure. Research limitations/implications: Results will be used for further steps which will consist of CVD process and other different heat treatment. Practical implications: This CVD method will be used in the future for the production of modified aluminide bond coats on single crystal Ni-base superalloys underlying the ceramic EB-PVD or LPPS top coatings. Originality/value: In the future the production of chemical vapor deposited platinum (or Pd, Zr, Hf) aluminide diffusion coatings on nickel base superalloy substrate are planned.