アトマイズ法によるＡｌ‐Ｐｂ合金粉末の凝固組織

Abstract

By blowing nitrogen gas into the molten state of Al-5 to 50%Pb alloys, which was discharged from the molten metal nozzle at the bottom part of graphite crucible, powder was produced. The solidification structure and cooling rate of the powder were examined. The results obtained are summarized as follows: The particle shape was not spherical but tear-drop-like, and the particle size was from 10 to 500 μm. It was found that lead particles were dispersed in the aluminum matrix in all the cases. The cooling rate of this powder was from 50 to 5800 k/s. The value of the heat transfer coefficient at the powder-gas interface was from 89 to 577 J/m2.s.k.