Use of gold powder alloys for manufacturing jewellery items by selective laser melting

• US 10,638,819 B2
• Filed: 05/18/2015
• Issued: 05/05/2020
• Est. Priority Date: 05/16/2014
• Status: Active Grant

• Current Assignee: Progold S.p.A. (Bluclad SpA)
• Original Assignee: Progold S.p.A. (Bluclad SpA)
• Inventors: Zito, Damiano
• Primary Examiner(s): Wyszomierski, George
• Application Number:
  US15/308,810
• Publication Number:
  US 20170164700A1
• Time in Patent Office: 1,814 Days
• Field of Search: None
• CPC Class Codes: A44C 27/003 Metallic alloys alloys in general C22C
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 10/38 to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 12/41 characterised by the type, e.g. laser or electron beam
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C22C 1/0425 Copper-based alloys
• CPC Class Codes: C22C 1/0466 Alloys based on noble metals
• CPC Class Codes: C22C 30/02 containing copper
• CPC Class Codes: C22C 5/02 Alloys based on gold
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A method of manufacturing yellow, red or white gold jewelry items layer by layer by selective laser melting (SLM) of a 18K, 14K, 10K or 9K gold powder alloy. The alloy comprises: (A) 37.5% to 38.5% by weight or 41.7% to 42.5% by weight or 58.5% to 59.5% by weight or 75% to 76% by weight of gold; and (D) 0.01% to 5% by weight, preferably 0.01% to 3% by weight of at least one metalloid, which may be germanium, silicon, boron, tellurium, phosphorous and selenium.

Claims

1. A method of manufacturing jewelry items layer by layer by selective laser melting (SLM) comprising:

providing a 18K, 14K, 10K or 9K yellow, red or white gold powder alloy; and

producing a jewelry item by melting the gold powder alloy into a plurality of adjoining layers with at least one laser beam,

wherein the at least one laser beam causes the gold powder in each layer to melt completely and produce homogeneous layers,

wherein the gold powder alloy consisting of a plurality of particles, each particle having a composition of;

(A) 37.5% to 38.5% by weight, 41.7% to 42.5% by weight, 58.5% to 59.5% by weight, or 75% to 76% by weight of gold (Au);

(B) X % to Y % by weight of a first element;

(C) X′

% to Y′

% by weight of a second element;

(D) 0.01% to 3% by weight of at least one metalloid;

and possible impurities;

wherein weight percentages are percentages by weight with respect to a total weight of the gold powder alloy;

wherein the at least one metalloid is selected from the group consisting of;

germanium (Ge), silicon (Si), boron (B), tellurium (Te), phosphorus (P), selenium (Se) or a mixture of two or more thereof;

wherein the gold powder alloy is free of gallium (Ga), platinum (Pt), and tin (Sn); and

wherein the gold powder allow further has a composition in which;

if the alloy is a yellow or red gold alloy;

(B) X is 10, Y is 55, and the first element is copper (Cu),

(C) X′

is 2, Y′

is 15, and the second element is silver (Ag),

and the yellow or red gold alloy is free of palladium (Pd);

if the alloy is a white gold alloy;

(B) X is 10, Y is 50, and the first element is palladium (Pd),

(C) X′

is 10, Y′

is 50, and the second element is silver (Ag),

wherein the palladium (Pd) and the silver (Ag) are in a weight ratio of 0.75;

1 to 1;

0.75, or

(B) X is 5, Y is 35, and the first element is nickel (Ni),

(C) X′

is 15, Y′

is 50, and the second element is copper (Cu),

wherein the nickel (Ni) and the copper (Cu) are in a weight ratio of 1;

2 to 1;

3.

2. The method of claim 1, wherein the gold powder alloy has a particle size of 1 μ

m to 60 μ

m.

3. The method of claim 1, wherein laser power is selected to melt completely and homogenously the gold powder hit by the at least one laser beam throughout a total height of a layer.

4. The method of claim 3, wherein the laser power is at least 70 Watt.

5. The method of claim 1, wherein the jewelry items have a total roughness Rt that is less than 65 μ

m.

6. The method of claim 1, wherein the jewelry items have an inner porosity in volume lower than 2%.

7. The method of claim 1, wherein the at least one metalloid is selected from the group consisting of:

germanium, silicon or boron, or a mixture of two or more thereof.

8. The method of claim 1, wherein providing the gold powder alloy comprises providing a gold powder alloy produced by atomization.

9. The method of claim 1, wherein the gold powder alloy is a 18K yellow or red gold alloy, and wherein:

(A) the gold is 75% to 76% by weight,

(B) the copper is 10% to 23% by weight,

(C) the silver is 2% to 15% by weight, and

(D) the at least one metalloid is 0.01% to 1% by weight.

10. The method of claim 1, wherein the gold is yellow gold, and wherein:

(B) the copper is 10% to 14% by weight, and

(C) the silver is 10% to 14% by weight.

11. The method of claim 1, wherein the gold is red gold, and wherein:

(B) the copper is 18% to 23% by weight, and

(C) the silver is 2% to 5% by weight.

12. The method of claim 1, wherein the gold powder alloy is a 14K red gold alloy, and wherein:

(A) the gold is 58.5% to 59.5% by weight,

(B) the copper is 30% to 40% by weight,

(C) the silver is 5% to 10% by weight, and

(D) the at least one metalloid is 0.01% to 1.5% by weight.

13. The method of claim 1, wherein the gold powder alloy is a 10K red gold alloy, and wherein:

(A) the gold is 41.7% to 42.5% by weight,

(B) the copper is 45% to 50% by weight,

(C) the silver is 8% to 13% by weight, and

(D) the at least one metalloid is 0.01% to 2% by weight.

14. The method of claim 1, wherein the gold powder alloy is a 9K red gold alloy, and wherein:

(A) the gold is 37.5% to 38.5% by weight,

(B) the copper is 47% to 55% by weight,

(C) the silver is 8% to 15% by weight, and

(D) the at least one metalloid is 0.01% to 3% by weight.

15. The method of claim 1, wherein the gold powder alloy is a 18K white gold alloy, and wherein:

(A) the gold is 75% to 76% by weight,

(B) the palladium is 10% to 15% by weight,

(C) the silver is 10% to 15% by weight, and

(D) the at least one metalloid is 0.01% to 1% by weight.

16. The method of claim 1, wherein the gold powder alloy is a 18K white gold alloy, and wherein:

(A) the gold is 75% to 76% by weight,

(B) the nickel is 5% to 10% by weight,

(C) the copper is 15% to 20% by weight, and

(D) the at least one metalloid is 0.01% to 1% by weight.

17. The method of claim 1, wherein the gold powder alloy is a 14K white gold alloy, and wherein:

(A) the gold is 58.5% to 59.5% by weight,

(B) the palladium is 15% to 25% by weight,

(C) the silver is 15% to 25% by weight, and

(D) the at least one metalloid is 0.01% to 1.5% by weight.

18. The method of claim 1, wherein the gold powder alloy is a 14K white gold alloy, and wherein:

(A) the gold is 58.5% to 59.5% by weight,

(B) the nickel is 8% to 20% by weight,

(C) the copper is 23% to 35% by weight, and

(D) the at least one metalloid is 0.01% to 1.5% by weight.

19. The method of claim 1, wherein the gold powder alloy is a 10K white gold alloy, and wherein:

(A) the gold is 41.7% to 42.5% by weight,

(B) the palladium is 25% to 45% by weight,

(C) the silver is 25% to 45% by weight, and

(D) the at least one metalloid is 0.01% to 2% by weight.

20. The method of claim 1, wherein the gold powder alloy is a 10K white gold alloy, and wherein:

(A) the gold is 41.7% to 42.5% by weight,

(B) the nickel is 12.5% to 35% by weight,

(C) the copper is 35% to 50% by weight, and

(D) the at least one metalloid is 0.01% to 2% by weight.