Method for preparing binder-free clad powders

A method of forming a binderless clad powder, said method comprising the steps of:

• (1) placing first and second materials in a drum of an attritor mill having a plurality of grinding balls, said attritor mill having a rotating shaft extending into said drum and said shaft having a plurality of impellers which set said grinding balls in motion, wherein said first material is selected from the group consisting of Fe, Ni, Co, Cu, Cr, Al, Ti, and alloys thereof and the second material is selected from the group consisting of Al, Ti, Ta, Mo, Si, Co, Ni, Fe, and alloys thereof, and wherein the first material is a powder and has a particle size in the range of about 10 to 200 microns, wherein the second material is a non-flake powder and has a particle size in the range of about 0.1 to 20 microns, wherein the particle size of the second material is significantly smaller than the particle size of the first material, and wherein at least one of the first and second materials is deformable within the high energy attritor mill;
• (2) processing said first and second materials in the high energy attritor mill in the absence of any binder material for a time sufficient to form a binderless clad powder but where the particle size of the first material is substantially unchanged during the processing, wherein the clad powder consists essentially of the first material forming the core of the powder and the second material coating the surface of the core;
• and
• (3) collecting the binderless clad powder.