Potential new experiments on fabrication of cast particulate composites in space

Recent developments in fabrication of cast metal ceramic particle composites by liquid metallurgy techniques are outlined. Difficulties encountered in preparing cast composites in the ground environment (including non-uniform distribution and agglomeration of dispersed particles and relatively poor bonding between dispersoids and matrix) and how these can be overcome in a microgravity environment have been discussed. This paper also reviews experiments performed by various space agencies including NASA and ESA on fabrication of composites in space. Some new experiments concerning fabrication of cast composites like dispersion of submicron ceramic particles in molten metals, preparation of cermets with very large volume fractions of ceramic particles and dispersion of flake-type ceramic particles to achieve grain refinement have been proposed.