Three-dimensional printing with redox-active inorganic salts

A method of making a three-dimensional printed object comprising:

• iteratively applying individual layers of a powder bed material to a powder bed, wherein the powder bed material consists of:
• polymer particles selected from the group consisting of polyamide 6 powder, polyamide 9 powder, polyamide 11 powder, polyamide 12 powder, polyamide 6,6 powder, polyamide 612 powder, thermoplastic polyamide powder, a polyamide copolymer powder, polyethylene powder, thermoplastic polyurethane powder, acrylonitrile butadiene styrene powder, polypropylene powder, polyester powder, polycarbonate powder, a polycarbonate and acrylonitrile butadiene styrene copolymer powder, a polycarbonate and polyethylene terephthalate polyether ketone copolymer powder, polystyrene powder, and mixtures thereof;
• an optional inorganic filler selected from the group consisting of alumina, silica, titanium dioxide, and carbon nanotubes;
• and
• a redox-active inorganic salt mixed with the polymer particles;
• based on a three-dimensional object model, selectively applying a fusing agent onto the individual layers of powder bed material, wherein the fusing agent comprises water and an electromagnetic radiation absorber, and wherein the electromagnetic radiation absorber absorbs electromagnetic radiation energy and converts the electromagnetic radiation energy to heat;
• and
• exposing the powder bed to electromagnetic radiation energy to selectively fuse the polymer particles in contact with the electromagnetic radiation absorber at individual layers and thereby form the three-dimensional printed object.

A system for three-dimensional printing comprising:

• a powder bed material consisting of:
• polymer particles selected from the group consisting of polyamide 6 powder, polyamide 9 powder, polyamide 11 powder, polyamide 12 powder, polyamide 6,6 powder, polyamide 612 powder, thermoplastic polyamide powder, polyamide copolymer powder, polyethylene powder, thermoplastic polyurethane powder, acrylonitrile butadiene styrene powder, polypropylene powder, polyester powder, polycarbonate powder, a polycarbonate and acrylonitrile butadiene styrene copolymer powder, a copolymer of polycarbonate and polyethylene terephthalate polyether ketone copolymer powder, polystyrene powder, and mixtures thereof;
• an optional inorganic filler selected from the group consisting of alumina, silica, titanium dioxide, and carbon nanotubes;
• and
• a redox-active inorganic salt mixed with the polymer particles;
• a fusing agent to selectively apply to a layer of the powder bed material, the fusing agent comprising water and an electromagnetic radiation absorber, wherein the electromagnetic radiation absorber absorbs electromagnetic radiation energy and converts the electromagnetic radiation energy to heat;
• and
• a radiant energy source positioned to expose the layer of powder bed material to electromagnetic radiation energy to selectively fuse the polymer particles in contact with the electromagnetic radiation absorber and thereby form a three-dimensional printed object.