Abstract: A method of 3D printing in which a 3D product is built up layer by layer by jetting from print heads includes forming part of a 3D product by a functional binder jetting process; jetting one or more material in a 2D pattern to form a structure on said part; completing the formation of the 3D product by continuing the functional binder jetting process, so that said structure becomes embedded in said product. Functional binder jetting may include: providing a layer of a powder bed; jetting a functional binder onto selected parts of said layer, wherein said functional binder infiltrates into pores in the powder bed and locally fuses particles of the powder bed in situ; sequentially repeating applying a layer of powder on top and selectively jetting functional binder, multiple times, to provide a powder bed bonded at selected locations by printed functional binder.

Abstract: A method of 3D printing a metal or alloy product includes providing a layer of a powder bed which comprises a compound of a first metal, and optionally also said first metal in elemental form and/or optionally other elemental metal(s) which are suitable for alloying with said first metal; jetting a functional binder onto selected parts of said layer, wherein said functional binder infiltrates into pores in the powder bed, reacts with said compound of a first metal to form said first metal in elemental form, and locally fuses elemental metal particles of the powder bed in situ, sequentially repeating said steps of applying a layer of powder on top and selectively jetting functional binder, multiple times, to provide a powder bed bonded at selected locations by printed functional binder and; taking the resultant bound 3D structure out of the powder bed.

Abstract: A method of 3D printing comprises: providing a layer of a powder bed; jetting a functional binder onto selected parts of said layer, wherein said binder infiltrates into pores in the powder bed and locally fuses particles of the powder bed in situ; sequentially repeating said steps of applying a layer of powder on top and selectively jetting functional binder, multiple times, to provide a powder bed bonded at selected locations by printed functional binder; and taking the resultant bound 3D structure out of the powder bed.