PURPOSE: To manufacture Al-Fe alloy powder simply, by allowing ingot of Al alloy contg. specific amount of Fe, P, C to stand and cool so as to collapse naturally.
CONSTITUTION: Molten metal of Al alloy, contg. 13.0W35.0 wt. % Fe, 0.05W1.0 wt. % P, 0.5W2.0 wt. % C, is cast and allowed to atand and cool to room temp. -20°CW+35°C. During the cooling, lattice strain and intergranular strain due to intermetallic cpds., e.g., fine Al13Fe4, Al5Fe2, AlFe2 etc., and Fe2P, Fe3P which are precipitated in the ingot of Al-Fe alloy increase internal stress. The stress concentrates at the grain boundary to produce microcrack, which as a trigger causes the ingot to collapse, finally to powder. The Al-Fe powder is most suitable for use in thermit reaction because of absence of oxidized film or nitrided coating on the surface.
ISHIDA YOUICHI
KIMURA SHIROU
KATOU TAKAYUKI
TABATA KOUZOU
KATO MASAO
ISHIDA YOUICHI