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Study on Crack‐like Pores of Al Foams Made via the Powder‐Metallurgy Route
Author(s) -
Wang Lei,
Yao Guangchun,
Liu Yihan,
Zu Guoyin
Publication year - 2010
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.200900195
Subject(s) - compaction , materials science , powder metallurgy , composite material , perpendicular , decomposition , stress (linguistics) , microstructure , geometry , ecology , linguistics , mathematics , philosophy , biology
Mechanisms for the formation and disappearance of the crack‐like pores generated during the early stage of Al foaming are investigated. A model for their disappearance process is proposed for the first time. The stress, perpendicular to the compaction direction in uniaxial cold compaction, is caused by the interaction of the Al powder under a high compaction pressure and is the main reason for the formation of the crack‐like pores. The results of the model analysis and theoretical calculations suggest that the pressure difference Δ P between the initial, round bubbles and the crack‐like pores is the driving force for their disappearance. The rapid reduction of Δ P is attributed to the decomposition characteristics of the TiH 2 powder.