A composite metal object comprises ductile crystalline metal particles in
an amorphous metal matrix. An alloy is heated above its liquidus
temperature. Upon cooling from the high temperature melt, the alloy
chemically partitions, forming dendrites in the melt. Upon cooling the
remaining liquid below the glass transition temperature it freezes to the
amorphous state, producing a two-phase microstructure containing
crystalline particles in an amorphous metal matrix. The ductile metal
particles have a size in the range of from 0.1 to 15 micrometers and
spacing in the range of from 0.1 to 20 micrometers. Preferably, the
particle size is in the range of from 0.5 to 8 micrometers and spacing is
in the range of from 1 to 10 micrometers. The volume proportion of
particles is in the range of from 5 to 50% and preferably 15 to 35%.
Differential cooling can produce oriented dendrites of ductile metal phase
in an amorphous matrix. Examples are given in the Zr--Ti--Cu--Ni--Be alloy
bulk glass forming system with added niobium.
