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» Revealing and evaluation of carbides in MAR M247 Ni based superalloy

The work presents carbide phases occurring in a structure of MAR M247 Ni based superalloy. The ways of revealing these phases and results of using optical, scanning electron and transmission microscopy as well as X-ray phase analysis for researches are presented (Fig. 1÷10). The author’s attention has been concentrated on the carbides morphology and places of occurrence. INTRODUCTION [...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2007/3-4

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» Influence of methodical factors on results of a quantitative evaluation of gamma' phase in MAR M247 superalloy

AGNIESZKA SZCZOTOK

The nickel-based superalloy MAR M247 is precipitation strengthened by coherent with matrix gamma' precipitates. The superalloy was investigated by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The scanning electron microscopy images were used for a stereological evaluation of the gamma' precipitates size and shape, density and volume fra[...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2008/4

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» Ilościowa ocena wielkości i kształtu ziaren pierwotnych w odlewanych precyzyjnie elementach z nadstopu kobaltu MAR-M509

JANUSZ ADAMIEC

AGNIESZKA SZCZOTOK

JAN CWAJNA

W artykule przedstawiono rezultaty prac badawczych nad makrostrukturą powierzchni roboczej (rys. 1, 3a, 4a) oraz makrostrukturą przekroju poprzecznego (rys. 2, 3b, 4b) żaroodpornego komponentu wykonan[...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2006/3

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» Application of a quantitative materialography methods for an evaluation of a structure repeatability of turbine blades made of MAR M247 nickel-based superalloy

AGNIESZKA SZCZOTOK

JAN CWAJNA

MARIAN MALIŃSKI

The results of studies on inhomogeneity of gas and shrinkage pores volume fraction, size and shape (Tab. 1) as well as size and shape of grains (Tab. 3) revealed during macroscopic analysis of experimental low pressure turbine blades of a jet engine made of MAR M247 nickel-based superalloy were characterized in the present work. The procedures of macro- and microstructure evaluation described[...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2008/4

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» Quantitative evaluation of γʹ phase in CMSX-4 superalloy

AGNIESZKA SZCZOTOK

TOMASZ RZYCHOŃ

JAN CWAJNA

The microstructure of nickel-base superalloys determines their mechanical behaviour. The strength of Ni-base superalloys is dependent on such factors as volume fraction, size, coarsening rate, and composition of γʹ phase precipitates [1]. The content and size of γʹ phase precipitates embedded in a cubic face-centred γ matrix can be adjusted by the alloy design and heat treatments. The composition of the ordered γʹ precipitates does differ, i.e. Ni3(Al, Ti, ...), and depends on the alloy composition and processing [2]. The characterization of γʹ phase precipitates in different nickelbased superalloys has been the subject of extensive research work. Volume fraction of the γʹ phase in Ni-base superalloys is a significant element influencing on working out the superalloys chemical compositions [3]. MATERIAL The measurements of γʹ phase precipitations were carried out on a monocrystalline cylindrical bar of 8 mm diameter made of CMSX-4 nickel-base superalloy [4]. The bar was cast in Laboratory of Material Research for Aircraft Industry in Rzeszów. The material was investigated in the as-cast condition. IMAGE ACQUISITION AND ANALYSIS OF γʹ PHASE PRECIPITATES The bar intended for investigations was cut perpendicularly to the main axis. The procedure of metallographic specimen preparation was described in details in Table 1. Quantitative metallography of CMSX-4 requires the revealing of γʹ precipitates by means of an appropriate etching conditions selection as well as use of appropriate image acquisition in order to observe the γʹ precipitates and register the images of the superalloy microstructure with them. In the previous work two etching methods of the γʹ phase precipitates were described [5]. For a quantitative evaluation of the precipitates etchant caused their etching and leaving the γ matrix is better, so in the ca[...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2010/3

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» Grain imaging and measurement on cross-section of turbine blade using EBSD and optical methods

Agnieszka Szczotok

Bartosz Chmiela

Maria Sozańska

Turbine blades are termed Flight Safety Parts (FSP). Imaging and measurement of grain in case of the blades is very important, because grain size, shape and distribution strongly affect the mechanical properties of the blades. The size and shape of primary grain are basic structural criteria for quality evaluation of precision cast products from nickel-based superalloys. The evaluation of fine-grained product is of great importance to metallurgists. This work which has traditionally been carried out using light microscopy can be performed by means of the electron backscattered diffraction (EBSD) technique used in the scanning electron microscope (SEM). EBSD is nowadays capable of undertaking such a study. EBSD has been known for many years (the diffraction of electrons was first observed in 1928 by Kikuchi [1]), but only widely applied in the last 10 years. EBSD is now a fast, automated technique which is utilized to determine microtexture (texture on the scale of the microstructure), microstructure quantification, grain and phase boundary characterization, phase identification and strain determination [2÷4]. EBSD is based on acquisition and analysis of Kikuchi diffraction patterns from the subsurface of a specimen in an SEM. In EBSD a stationary electron beam strikes a tilted crystalline sample and the diffracted electrons form a pattern on a fluorescent screen. The diffraction pattern can be used to measure the crystal orientation, as well as boundary misorientations, discriminate between different materials, and provide information about local crystalline perfection. When the beam is scanned in a grid across a polycrystalline sample and the crystal orientation is measured at each point, the resulting map reveals the constituent grain morphology, orientations and boundaries. Electron backscatter diffraction technique to measure grain-specific orientations and misorientations was first recorded more than 20 years ago [5] and[...] więcej»
w zeszycie INŻYNIERIA MATERIAŁOWA 2010/3

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