Grain refiners as liquid metal foam stabilisers

Publications

Grain refiners as liquid metal foam stabilisers

Year : 2007

Source Title : Transactions of the Indian Institute of Metals

Document Type :

Abstract

The present work reports on the foaming of liquid aluminium containing TiB2, TiC or TiAl3 particles (4-11.5 vol.%) which were prepared in-situ by flux-assisted melting using fluorides. This procedure was in analogy to the production of composites containing grain refining particles. The particle size was kept below 1 μm for TiB2 and TiC and around 10 μm for TiAl3. Foams were successfully produced using TiB 2 and TiC particles and thus it could be demonstrated for the first time that metal foams can be stabilised by sub-micrometre particles. The influence on foam stability of alloying with Si and dilution of the melt with pure Al was studied in addition. Microstructural analysis of the foams showed that the particles segregate to the surfaces of cell walls leading to an almost dense coverage, thus helping in stabilising the foams.