Three-dimensional printing of metal objects using binding agent with copper nitrate
The present disclosure is drawn to a three-dimensional printing kit and can include a particulate build material including from about 80 wt % to about 100 wt % metal particles, and a binding agent including water, from about 0.01 wt % to about 5 wt % organic compounds, and from about 20 wt % to about 60 wt % copper nitrate.
1 . A method of three-dimensional printing, the method comprising:
iteratively applying individual layers of a particulate build material comprising from about 80 wt % to about 100 wt % of metal-containing particles;
based on a 3D object model, selectively and iteratively applying a binding agent to the individual layers of the particulate build material to define a green body object formed from multiple individual layers within a powder bed of the particulate build material, wherein the binding agent comprises an aqueous liquid vehicle and a copper nitrate; and
heat curing the green body object by heat soaking the green body object at a temperature of from about 70° C. to about 200° C. for a time period of from about 30 minutes to about 8 hours after the green body object is formed,
wherein after the heat curing, from about 30 wt % to 100 wt % of the copper nitrate in the green body object is in the form of copper hydroxynitrate.
2 . The method of claim 1 , wherein the particulate build material comprises from about 95 wt % to about 100 wt % of copper.
3 . The method of claim 1 , wherein the metal-containing particles are selected from the group consisting of aluminum particles, aluminum alloy particles, titanium particles, titanium alloy particles, copper particles, copper alloy particles, cobalt particles, cobalt alloy particles, chromium particles, chromium alloy particles, nickel particles, nickel alloy particles, vanadium particles, vanadium alloy particles, tungsten particles, tungsten carbide particles, tantalum particles, tantalum alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, gold particles, gold alloy particles, silver particles, silver alloy particles, ferrous alloy particles, stainless steel particles, steel particles, and an admixture thereof.
4 . The method of claim 1 , wherein the aqueous vehicle of the binding agent comprises organic compounds, and wherein from about 60 wt % to 100 wt % of the organic compounds are in the form of an organic co-solvent, a surfactant, or a combination thereof.
5 . The method of claim 1 , wherein the copper nitrate is a hydrated copper nitrate.
6 . The method of claim 1 , wherein the heat curing of the green body object is at a temperature of from about 70° C. to about 120° C. for a time period of from about 30 minutes to about 4 hours while the green body object is within the powder bed.
7 . The method of claim 1 , further comprising:
removing the green body object from the powder bed; and
further heat curing the green body object at a temperature of from about 120° C. to about 200° C. for a time period of from about 30 minutes to about 8 hours.
8 . The method of claim 1 , wherein the heat curing of the green body object occurs at a temperature of from about 70° C. to about 120° C. for a time period of about 30 minutes to about 4 hours while the green body object is within the powder bed, and the method further comprises subsequently heat curing the green body object at a temperature of from about 120° C. to about 200° C. for a time period of from about 30 minutes to about 8 hours after removing the green body object from the powder bed.
9 . The method of claim 1 , wherein after the heat curing, from about 75 wt % to 100 wt % of the copper nitrate in the green body object is copper hydroxynitrate.
10 . The method of claim 1 , further comprising fusing the green body object in a fusing oven at a fusing temperature of from about 600° C. to about 3,500° C. for a time period of from about 1 hour to about 30 hours to form a heat-fused, metal-containing object.