Porous metal structures and processes for their production

A porous metal component having controlled microporosity produced by a process which comprises the sequential steps of:

• preparing a colloidal suspension comprising at least one metal powder having a particle size less than 300 microns, in admixture with a binder system, a plasticizer, a solvent and a pyrolysable, particulate pore-forming agent;
• casting said colloidal suspension into a thin sheet;
• drying said sheet to thereby form a tape having preselected pliability properties;
• layering a predetermined number of tape layers, and compacting said layers at pressures ranging from between about 5 to 60 MPa at temperatures in the range of between about 25.degree. to 800.degree. C. for a time effected to laminate said layers of tape and form a green body;
• heating said green body at a controlled rate, at temperatures effective to remove the pyrolysable additives and form a brown body;
• and
• sintering said brown body at a temperatures in the range of between about 700.degree. to 1400.degree. C. to thereby form a porous metal structure.

A porous metal component having controlled macroporosity produced by a process which comprises the sequential steps of:

• preparing a colloidal suspension comprising at least one metal powder having a particle size less than 300 microns, in admixture with a binder system, a plasticizer, and a solvent;
• casting said colloidal suspension into a thin sheet;
• drying said sheet to thereby form a tape having preselected pliability properties;
• layering a predetermined number of tape layers, and providing a pyrolysable, pore-forming agent in association with said layers prior to compacting said layers at pressures ranging from between about 5 to 60 MPa at temperatures in the range of between about 25.degree. to 80.degree. C. for a time effective to laminate said layers of tape and form a green body;
• heating said green body at a controlled rate, at temperatures effective to remove the pyrolysable additives and form a brown body;
• and
• sintering said brown body at temperatures in the range of between about 700.degree. to 1400.degree. C. to thereby form a porous metal component.

A porous metal component having controlled microporosity and macroporosity produced by a process which comprises the sequential steps of:

• preparing a colloidal suspension comprising at least one metal powder, having a particle size less than 300 microns, in admixture with a binder, a dispersant, a plasticizer, a solvent and a first pore-forming agent;
• casting said colloidal suspension into a thin sheet;
• drying said sheet to thereby form a tape having preselected pliability properties;
• layering a predetermined number of tape layers, and providing a second pyrolysable, pore-forming agent in association with said layers prior to compacting said layers at pressures ranging from between about 5 to 60 MPa at temperatures in the range of between about 25.degree. to 800.degree. C. for a time effective to laminate said layers of tape and form a green body;
• heating said green body at a controlled rate, at temperatures effective to remove the pyrolysable additives and form a brown body;
• and
• sintering said brown body at temperatures in the range of between about 700.degree. to 1400.degree. C. to thereby form a porous metal structure.