Particulate compositions comprising a metal precursor for additive manufacturing and methods associated therewith
Additive manufacturing processes, such as powder bed fusion of thermoplastic particulates, may be employed to form printed objects in a range of shapes. It is sometimes desirable to form conductive traces upon the surface of printed objects. Conductive traces and similar features may be introduced during additive manufacturing processes by incorporating a metal precursor in a thermoplastic printing composition, converting a portion of the metal precursor to discontinuous metal islands using laser irradiation, and performing electroless plating. Suitable printing compositions may comprise a plurality of thermoplastic particulates comprising a thermoplastic polymer, a metal precursor admixed with the thermoplastic polymer, and optionally a plurality of nanoparticles disposed upon an outer surface of each of the thermoplastic particulates, wherein the metal precursor is activatable to form metal islands upon exposure to laser irradiation. Melt emulsification may be used to form the thermoplastic particulates.
1. A particulate composition comprising: a plurality of thermoplastic particulates each having an outer surface and an interior, the thermoplastic particulates comprising a metal precursor admixed with a thermoplastic polymer within the interior of the thermoplastic particulates, a plurality of nanoparticles disposed upon the outer surface of the thermoplastic particulates, the plurality of nanoparticles being in contact with the thermoplastic polymer at the outer surface and comprising a plurality of silica nanoparticles, carbon black, or combination thereof,
the metal precursor being activatable to form metal islands upon exposure to laser irradiation.
2. The particulate composition of claim 1 , wherein the metal precursor is activatable by an infrared or near-infrared pulsed laser.
3. The particulate composition of claim 1 , wherein the metal precursor is activatable at a wavelength ranging from about 1020 nm to about 1070 nm.
4. The particulate composition of claim 1 , wherein the metal precursor comprises at least one material selected from the group consisting of copper oxide; a mixed oxide of copper and a metal selected from the group consisting of antimony, aluminum, cesium, cobalt, chromium, magnesium, manganese, nickel, tin, titanium, silver, iron, zinc, and zirconium; copper chromium oxide spinel; copper aluminum oxide; copper hydroxide; copper hydroxide phosphate; copper phosphate; copper sulfate; copper thiocyanate; a metal-organic complex comprising a metal selected from the group consisting of copper, silver, palladium, and any combination thereof; and any combination thereof.
5. The particulate composition of claim 1 , further comprising:
an infrared radiation absorber admixed with the thermoplastic polymer;
wherein the infrared radiation absorber comprises a non-stoichiometric metal oxide containing a metal selected from the group consisting of antimony, bismuth, boron, indium, titanium, tin, cesium, zirconium, molybdenum, vanadium, iron, and any combination thereof.
6. A method comprising: depositing in a powder bed a particulate composition comprising a plurality of thermoplastic particulates each having an outer surface and an interior, the thermoplastic particulates comprising a metal precursor admixed with a thermoplastic polymer within the interior of the thermoplastic particulates, wherein the plurality of thermoplastic particulates further comprise a plurality of nanoparticles disposed upon the outer surface of the thermoplastic particulates, the plurality of nanoparticles being in contact with the thermoplastic polymer at the outer surface and comprising a plurality of silica oxide nanoparticles, carbon black, or any combination thereof;
the metal precursor being activatable to form metal islands upon exposure to laser irradiation; and consolidating a portion of the plurality of thermoplastic particulates in the powder bed to form a printed object in which the metal precursor remains substantially unconverted to metal.
7. The method of claim 6 , wherein the metal precursor comprises at least one material selected from the group consisting of copper oxide; a mixed oxide of copper and a metal selected from the group consisting of antimony, aluminum, cesium, cobalt, chromium, magnesium, manganese, nickel, tin, titanium, silver, iron, zinc, and zirconium; copper chromium oxide spinel; copper aluminum oxide; copper hydroxide; copper hydroxide phosphate; copper phosphate; copper sulfate; copper thiocyanate; a metal-organic complex comprising a metal selected from the group consisting of copper, silver, palladium, and any combination thereof; and any combination thereof.
8. The method of claim 6 , wherein the metal precursor is activatable with an infrared or near-infrared pulsed laser.
9. The method of claim 6 , further comprising:
activating a portion the metal precursor within the printed object using a pulsed laser to form a plurality of discontinuous metal islands in a predetermined pattern upon a surface of the printed object.
10. The method of claim 9 , further comprising:
performing electroless plating to form one or more conductive traces interconnecting the plurality of discontinuous metal islands.
11. The particulate composition of claim 1 , wherein the metal precursor is dispersed as metal precursor particulates in the thermoplastic polymer, the metal precursor particulates having a particle size ranging from about 10 nm to about 1000 nm.