Author/Editor		Konopka, Katarzyna; Ozieblo, Artur; Kurzydlowski, Krzysztof Jan
Title		Quantitative descriptive of the Fe and Mo particles in Al2O3 matrix composites
Type		članek
Source		Image Anal Stereol
Vol. and No.		Letnik 20, št. Suppl 1
Publication year		2001
Volume		str. 487-91
Language		eng
Abstract		The paper describes the result of the quantitative description of the microstructure of a series of composites of Al2O3 modified with Fe/Mo particles sintered at 1770°C. Computer methods have been used to analyze representative images of the composite microstructures. The average size of Mo particles in the Al2O3-Mo cermets has been found to be higher than the size of particles in the Mo powder. Since, molybdenum does not melt during sintering, it is concluded that during the sintering Mo particles agglomeration takes place. This process is accelerated by a small distance between the particles. The opposite situation is observed in composites containing iron. Comparing with the size of the particles in the powder, the average size of Fe particles in sintered materials is lower. This decrease in the size of Fe particles is explained in tenns of iron melting and redistribution into the pores present in the ceramic matrix. The indentation fracture toughness (Kc) of ceremets was also analyzed. The fracture toughness in both cennets is higher than for Al2O3. The highest values of K` were measured for Al2O3-Mo cermets. The increase in the value of Kc is proportional to the fraction of Mo. For Al2O3-Fe cermets the maximum fracture toughness is observed for the specimens containing 30 wt.% of Fe. This effect can be attributed to the formation of FeAl2O4 spinel during the sintering of Al2O3-Fe composites.
Descriptors		MATERIALS TESTING CERMET CEMENTS PARTICLE SIZE IMAGE PROCESSING, COMPUTER-ASSISTED IRON MOLYBDENUM ALUMINUM COMPOUNDS