Product forming molds and methods to manufacture same
Product forming molds have surfaces conformally coated with a coating composite comprising superabrasive particles. In one embodiment, the mold surface is plated (electrolessly or electrolytically) or coated with a metal having superabrasive particles dispersed therein. In another embodiment, the composite is a SiC composite having superabrasive particles dispersed therein.
1. An article comprising:
a mold having a shaped surface;
wherein one or more portions of the surface comprise a particulate superabrasive material in a matrix;
wherein the superabrasive material comprises discrete superabrasive particles and wherein the matrix comprises a metal alloy; and
wherein the mold surface is shaped and positioned to contact a material heated above a working point of the material during a molding process.
2. The article of claim 1 wherein the conformal surface layer contacts a metal substrate.
3. The article of claim 1 wherein the metal alloy includes nickel.
4. The article of claim 1 wherein the mold is patterned to make one or more of a design, image or character on a molded object.
5. The article of claim 1 wherein the matrix is heat treated to increase a hardness of the matrix.
6. The article of claim 1 wherein the superabrasive material is selected from the group consisting of diamond, cubic boron nitride, and mixtures thereof.
7. The article of claim 1 wherein the matrix further includes abrasive particles chosen from the group consisting of SiC, Si 3 N 4 , WC, TiC, CrC, B 4 C, SiO 2 , Al 2 O 3 , and ZrB 2 .
8. The article of claim 1 wherein the matrix further includes lubricating particles chosen from the group consisting of graphite, MoS 2 , hexagonal boron nitride, or combinations of these.
9. The article of claim 1 further comprising a strike layer between the conformal surface layer and a mold substrate.
10. The article of claim 1 wherein the metal alloy matrix comprises a nickel phosphorus alloy.
11. The article of claim 1 wherein the conformal surface layer comprises a substantially uniform thickness.
12. The article of claim 1 wherein the conformal surface layer comprises a substantially even thickness on a wall and a bottom of a hole in the mold.
13. The article of claim 1 wherein the conformal surface layer has a thickness measured at any point normal to a feature of the mold of about plus or minus 10% of an average conformal surface layer thickness at any point normal to a second feature of the mold.
14. The article of claim 1 wherein the conformal surface layer contacts an electrically non-conductive substrate.
15. The article of claim 1 wherein the conformal surface layer preserves a fine detail of the shaped surface of the mold.
16. An article comprising:
at least one mold surface that shapes molten material in a molding process;
wherein the mold surface is coated with an adherent conformal coating comprising discrete superabrasive particles in a metal alloy matrix so that the coating contacts the molten material.
17. The article of claim 16 wherein the surface is part of a plunger, a gob knife, a mold, a gob orifice, a mold neck ring, an extruder, blowtip, diverter chute, or extrusion die.
18. The article of claim 16 wherein the superabrasive particles comprise diamond, cubic boron nitride, a mixture of these, or a mixture containing these and other abrasive materials.
19. The article of claim 16 wherein the metal alloy matrix includes nickel.
20. The article of claim 16 further comprising a strike layer between the coating and the mold surface.