LIGHTWEIGHT METAL WITH ISOLATED PORES AND ITS PRODUCTION

摘要

A novel lightweight gas-metal composite is produced having isolated particle-stabilized pores. A composite of a metal matrix, e.g. aluminum, and finely divided solid stabilizer particles, e.g. silicon carbide, is heated above the liquidus temperature of the metal matrix and this is mixed such that a vortex is formed. The molten composite is blanketed with a gas and during the vortex mixing. This gas is drawn into the melt to produce an expanded, viscous molten composite material containing pores which are very small, spherical-shaped and quite evenly distributed. The viscous molten composite material can be directly formed into a solid shaped product and is also capable of being remelted and formed by forming processes without destroying the integrity of the pores. The result is a lightweight expanded metal product capable of being formed into shapes to close dimensional tolerances.