Process and apparatus to simultaneously consolidate and reduce metal powders

In a process for making an integral, mechanically hot workable metal body from powder, the steps of

• providing a porous charge of metal powder particles having a predetermined composition and volume;
• forcing a reactive fluid to flow into an inlet portion of the charge while confining the reactive fluid to the volume of the charge, such that it substantially completely permeates the pores of said charge and flows out of an outlet portion thereof;
• heating said charge to a consolidation temperature at which solid state sintering of the metal powder particles occurs but below the incipient melting point of the metal powder while said reactive fluid is in contact with said metal powder and thereby modifying the chemistry of at least the surfaces of the metal powder particles in a predetermined manner;
• applying an external force to said charge as it is heated, so as to partially compact it while leaving it porous to the reactive fluid flowing therethrough said external force being distinct from any force caused by the flow of the reactive fluid through said charge
• thereafter removing said reactive fluid from said metal powder charge;
• and then
• further compacting the metal powder to a density greater than about 90% of the full theoretical density of said predetermined composition.