Author/Editor		Lacaze, Jacques; Arnal, Alexis; Dupuy, Jean-Luc; Poquillon, Dominique
Title		Separation of the inter- and intra-particle porosity in images of powder compacts
Type		članek
Source		Image Anal Stereol
Vol. and No.		Letnik 21, št. 3
Publication year		2002
Volume		str. 183-9
Language		eng
Abstract		Powder metallurgy is a highly developed and cheap method of manufacturing reliable materials, either metallie, ceramic or composite. This process was used to make green compacts of iron powders with a high porosity level. This study is part of a project aimed at describing the relationships between mechanical properties and morphological features of such compacts, with particular attention paid to the shape of the grains and the compaction pressure. In this report, a method is proposed to separate the intra grain porosity from the cavities located between particles. The approach is based on the covariogram of images obtained from the surface of the compacts by means of a laser roughometer. To achieve this separation, a model of the structure is proposed which assumes that the distributions of the grains and of the intra-particle cavities are random and independent. Each distribution is characterized by two parameters. A satisfactory agreement is obtained between experimental and calculated covariograms after identification of these parameters.
Descriptors		MATERIALS TESTING IRON PARTICLE SIZE MICROSCOPY, ELECTRON, SCANNING IMAGE PROCESSING, COMPUTER-ASSISTED POROSITY METALLURGY