Published by De Gruyter

Volume 42 Issue 11

Issue of Practical Metallography

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Contents
Journal Overview

Contents/Inhalt

June 11, 2013

Inhalt / Contents

Page range: 531-531

Technical Contributions/Fachbeiträge

June 11, 2013

A Study on the Creep Cavitation in an Ni3Al Alloy Using the Hydrogen Embrittlement Technique

Ho-Kyung Kim, Sung-Hoon Kim, Chang-Young Hyun

Page range: 533-545

Abstract

In this study, the hydrogen embrittlement technique was employed in order for the direct observation of entire cavities on exposing grain boundary facets in a Ni3Al alloy. Also, stereo pair SEM micrographs were used to investigate the effects of inclined angle of grain boundary on cavity growth, by comparing relative positions of features on the stereo pair. Many of cavities at 65% of the rupture time are on the verge of coalescing with other cavities. Cavities on inclined boundaries had grown for longer time than those on transverse boundaries. Thus, the time to cavity coalescence on transverse facets are lower bound of the material lifetime. And, overall damage was found to have the value of about 0.6 at rupture.

June 11, 2013

TEM-Untersuchungen an Erosionskratern, die durch elektrische Entladungen erzeugt werden

Flavio Soldera, Nenad Ilic, Frank Mücklich

Page range: 546-554

Abstract

Kurzfassung Durch elektrische Plasmaentladungen wurden Krater an der Materialoberfläche einer Pt-Probe erzeugt. Mittels FIB wurden TEM-Lamellen der Kraterquerschnitte präpariert, um die Gefügeänderung nach dem Entladungseinschlag zu beobachten. Das Material, das im flüssigen Zustand zum Kraterrand verschoben wurde, konnte identifiziert werden. Unter diesem Kraterrand bilden sich Mikroporen. Die Körner unter dem Krater erstrecken sich bis an die Krateroberfläche durch epitaxiales Wachstum.

June 11, 2013

2D Quantitative Characterization of Microstructural Inhomogeneities in the Pressure Die Cast AZ91 Magnesium Alloy

D.G. Leo Prakash, Doris Regener

Page range: 555-575

Abstract

Inclusions, shrinkage pores and gas pores are the major processing defects of pressure die cast AZ91 magnesium alloy. These inhomogeneities influence the mechanical properties of the material. Hence, quantitative characterization of size and arrangement of inclusions, shrinkage and gas microporosity is expected to be useful to understand the processing-property-microstructure correlation. In the present work an image analysis procedure has been explained to separately quantify the above inhomogeneities. The important parameters of image processing like montage creation, magnification selection and shrinkage pore separation are explained. The inclusions, shrinkage and gas micropores were separated by the above procedure and size, nearest neighbor distance distributions of these inhomogeneities were obtained in order to characterize the material.

About this journal

Practical Metallography is a bilingual (German-English) journal that informs you thoroughly on materialographic preparation, imaging and analysis of microstructures. The journal covers the development and improvement of metallographic methods and equipment, possibilities of optical and electron microscopy, spectroscopy, diffraction techniques, non-destructive testing, metallographic investigations of materials, problems of specimens preparation and evaluation including useful laboratory advice and recipes, failure analysis including damage detection and elimination.
All articles are subject to thorough, independent peer review.
Practical Metallography works closely with Deutsche Gesellschaft für Materialkunde e.V. (DGM)