Process for fabricating parts from particulate material

A method of manufacturing sintered metal parts consisting essentially of:

• (i) mixing together predetermined amounts of powdered particulate material and a binder to produce a liquid slurry mixture, said binder being comprised of at least two components having differing melting points, at least a lower melting point component and a higher melting point component, with the lower melting point component remaining in a liquid state, becoming semi-solid or relatively soft upon cooling to ambient temperatures and comprising an oil or a mixture of an oil and wax, and with the higher melting point component comprising polypropylene or polyethylene;
• (ii) molding the mixture of particulate material and binder into a part of desired shape by injecting said mixture under heat and pressure into a mold, and allowing said mixture to solidify;
• (iii) removing the lower melting point component of the binder by placing the part in a liquid solvent, the solvent comprising methylene chloride, acetone or naphtha, which solvent selectively dissolves the lower melting point component and leaves at least the higher melting point component of the binder undissolved, rendering said part porous and free of cracks;
• (iv) removing the high melting point component of the binder by heating at a temperature in the range of from about 700.degree. F. to about 1400.degree. F. to thereby provide part which is essentially free of binder;
• and
• (v) subjecting the binder-free part to a final sintering temperature in order to complete the sintering.