Fabrication of metallic parts by additive manufacturing

A method of fabricating a three-dimensional object, the method comprising:

• providing a dry powder bed containing a powder comprising a plurality of substantially spherical composite particles each comprising a mixture and/or alloy of a first constituent metal and one or more second constituent metals, wherein (i) the particles have a Hall flow rate ranging from approximately 1 s/50 g to approximately 25 s/50 g, and (ii) an outer surface of each of the particles comprises a plurality of grains, each grain being surrounded by a matrix, the grains comprising the first constituent metal, and the matrix comprising the one or more second constituent metals;
• forming a first layer of a shaped part by (i) dispersing a binder into the powder bed, and (ii) curing the binder, the first layer of the shaped part comprising particles bound together by cured binder;
• disposing a layer of the particles over the first layer of the shaped part;
• forming subsequent layers of the shaped part by (i) dispersing binder over the particles, and (ii) curing the binder, additional particles being disposed over the shaped part between layers;
• and
• sintering the shaped part to form the three-dimensional object.