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1

The 2D characterization of pores shape in sintered material before and after deformation

Chrapoński Jacek, Roskosz Stanisław, Madej Łukasz

Inżynieria Materiałowa

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2019

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Vol. 40, nr 4

98--102

EN

The specimens sintered from Distaloy AB iron powder have been examined to evaluate evolution of morphological characteristics under complex deformation conditions. The sintering procedure, in particular, the pressure and the temperature have been adjusted in order to obtain about a 15% porosity level. All examinations were performed on the specimen in as-sintered state, as well as after plastic deformation (compression with cyclic torsion). The volume fraction and pores shape have been described quantitatively before and after deformation. On the basis of statistical analysis, it was found that compression with cyclic torsion with amplitude 3° and frequency 0.5 Hz better reduce porosity than deformation with amplitude 6° and frequency 1 Hz. All shape factors that were used to describe pores geometry, except convexity, differ significantly after plastic deformation in comparison to values before deformation. The Principal Component Analysis of the pores shape factors showed, that it is possible to reduce the characterization of the pores to two principal components. Alternatively, it is sufficient to fully characterize pores shape with three shape factors: circularity, Malinowska’s factor and not correlated with them aspect ratio.

PL

Właściwości materiałów porowatych silnie zależą od cech geometrycznych porów: ich objętości względnej, wielkości, kształtu, rozmieszczenia itp. Odkształcenie plastyczne materiałów porowatych jest procesem, który zmienia ich właściwości, również wskutek zmiany cech porowatości. W trakcie odkształcenia plastycznego morfologia i liczba porów zmienia się, wpływając na właściwości materiału. Kontrola i możliwość kształtowania właściwości materiałów porowatych wymaga wiedzy dotyczącej zmian morfologii porów, przede wszystkim kształtu określanego na podstawie pomiarów na obrazach mikrostruktury zarejestrowanych podczas badań zgładów metalograficznych. Celem pracy było określenie zmian objętości względnej i kształtu porów po ściskaniu z cykliczną rotacją spiekanych próbek oraz dobór współczynników kształtu porów najlepiej charakteryzujących morfologię porów po odkształceniu plastycznym.

2

The thumb carpometacarpal joint: curvature morphology of the articulating surfaces, mathematical description and mechanical functioning

Dathe H., Dumont C., Perplies R., Fanghänel J., Kubein-Meesenburg D., Nagerl H., Wachowski M. M.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 2

103--110

EN

Purpose: The purpose is to present a mathematical model of the function of the thumb carpometacarpal joint (TCMCJ) based on measurements of human joints. In the TCMCJ both articulating surfaces are saddle-shaped. The aim was to geometrically survey the shapes of the articulating surfaces using precise replicas of 28 TCMCJs. Methods: None of these 56 articulating surfaces did mathematically extend the differential geometrical neighbourhood around the main saddle point so that each surface could be characterised by three main parameters: the two extreme radii of curvature in the main saddle point and the angle between the saddles’ asymptotics (straight lines). Results: The articulating surfaces, when contacting at the respective main saddle points, are incongruent. Hence, the TCMCJ has functionally five kinematical degrees of freedom (DOF); two DOF belong to flexion/extension, two to ab-/adduction. These four DOF are controlled by the muscular apparatus. The fifth DOF, axial rotation, cannot be adjusted but stabilized by the muscular apparatus so that physiologically under compressive load axial rotation does not exceed an angle of approximately ±3°. Conclusions: The TCMCJ can be stimulated by the muscular apparatus to circumduct. The mechanisms are traced back to the curvature incongruity of the saddle surfaces. Hence we mathematically proved that none of the individual saddle surfaces can be described by a quadratic saddle surface as is often assumed in literature. We derived an algebraic formula with which the articulating surfaces in the TCMCJ can be quantitatively described. This formula can be used to shape the articulating surfaces in physiologically equivalent TCMCJ-prostheses.

3

Quantitative procedure for evaluation of microstructure of cast Mg-Al-Ca-Sr magnesium alloy

Rzychoń T.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1 spec.

139--142

EN

In this paper the microstructural characterization of ingot MRI-230D magnesium alloy and quantitative procedure for evaluation of microstructure are presented. The optical and scanning electron microscopy were used to study the morphology of microstructural compounds in this alloy. The X-ray diffraction was used to determination of phase composition. The as-cast microstructure of MRI-230D magnesium alloy containing aluminum, calcium and strontium consists of the dendritic α-Mg and such intermetallic compounds as: Al2Ca, Al4Sr and AlxMny. In the purpose quantitative description of microstructure semi-automatic procedures using Met-Ilo image analysis were developed. Prepared semi-automatic procedures allow a fast determination of phase content in MRI-230D alloy using light microscopy and will be useful in the quality control of MRI-230D ingots.

4

Image based analysis of complex microstructures of engineering materials

Wejrzanowski T., Spychalski W. L., Różniatowski K., Kurzydłowski K. J.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 1

33-39

EN

The paper presents various methods for quantitative description of material structures. The main focus is on direct methods of description based on image analysis. In particular, techniques for the estimation of the size, shape and spatial distribution of structural elements observed by different microscopic techniques are described. The application of these methods for the characterization of the structures of engineering materials is demonstrated on a stainless steel used in petrochemical installations. It is shown that the methods applied are useful for the assessment of service degradation of materials.

5

Quantitative metallography of Armco-iron with microstructure gradient.

Bucki J.J., Wejrzanowski T.

Inżynieria Materiałowa

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2001

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R. XXII, nr 4

237-240

EN

An approach has been made to provide quantitative description of three types of gradient materials produced on a base of Armco iron. Three different technologies have been used to obtain microstructure gradient: surface engineering, cold drawing and annealing and powder metallurgy. Each of studied materials has different type of gradient forming element of structure - starting from gradient of needles length in case of material after surface treatment by gradient of grain size in cold drawn and annealed one, to gradient of porosity in the sintered material. This calls for different approach to description of the gradient. In all cases studied traditional approach of computing only global parameters of microstructure leads to, at best, incomplete description.

PL

Przedstawiono ilościowy opis trzech typów materiałów gradientowych na bazie żelaza Armco otrzymanych poprzez zastosowanie różnych technologii. Pierwszy z materiałów uzyskano metodami inżynierii powierzchni, drugi poprzez zgniot na zimno i wyżarzanie, a ostatni technikami metalurgii proszków. Każdy z badanych materiałów posiadał inny typ gradientu - zaczynając od gradientu długości igieł, poprzez gradient wielkości ziarna, a skończywszy na gradiencie porowatości. Tradycyjne metody opisu pozwalają jedynie na uzyskanie globalnych parametrów, co nie daje pełnej charakterystyki zmian struktury w tego typu materiałach.

6

Zastosowanie komputerowej analizy obrazu do ilościowego opisu powierzchni niepłaskich

Cybo J., Gołąb A., Chmiela J., Stach S., Maszybrocka J.

Krzepnięcie Metali i Stopów

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2000

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R. 2, nr 44

425--433

PL

Przedstawiono zastosowanie komputerowej analizy obrazu do ilościowego opisu powierzchni niepłaskich (PNP). Problem omówiono na ogólnym przypadku PNP, np. przełomu ciągliwego, oraz dla konkretnego przykładu analizy powierzchni szlifowanej, dla której wyznaczono ok. 20 parametrów topograficznych i krzywe nośności. Podano wytyczne wykorzystania metody analizy obrazu dla omawianych zastosowań oraz ocenę dokładności rozwiązania.

EN

The application of computer-aided image analysis for quantitative description of non-planar surfaces (NPS) is shown. The problem was discussed on the basis of NPS general case e.g., ductile fracture and for actual example of analysis of grinned surface. About 20 topographical parameters as well as load capacity curves were determined for that surface. The directions of using the image analyzing method for considered applications as well estimation of precision of the method is given.

7

Quantitative Description of the Microstructure of Ceramic Materials

Kurzydłowski K.J., Bucki J., Rożniatowski K.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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1999

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Vol. 47, nr 4

353-364

EN

The aim of the present paper was to demonstrate that a quantitative description of the microstructure of an advanced ceramic material can be efficiently obtained using modern computer-aided methods. Such a description is necessary for realistic modelling of properties and perhaps may lead to improvements in the technology of producing such materials.