Hardfaced wear part using brazing and associated method and assembly for manufacturing

Patent metadata

Field	Value
Publication number	US-10730104-B2
Application number	US-201715398699-A
Country	US
Kind code	B2
Filing date	Jan 4, 2017
Priority date	Apr 6, 2011
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

An article, such as a hardfaced wearpart, includes a substrate, a sheet metal shell connected to the substrate to define a cavity between the surface of the substrate and the shell, and a composite material filling the cavity and forming a coating on at least a portion of the surface of the substrate, the composite material including a hard particulate material infiltrated with a metallic brazing material. The shell may be connected to the substrate by welding or brazing to the substrate, and may wear away during use. The shell and the substrate may be used as part of an assembly for producing the article, where the shell is used as a mold for forming the composite material by filling the shell with the hard particulate material and subsequently infiltrating with the brazing material.

First claim

What is claimed is:

1. A method for making a wear part for earth engaging equipment comprising:
providing a metal substrate formed for attachment to earth engaging equipment, the metal substrate having a surface;
connecting by welding or brazing an expendable, thin sheet metal shell to the surface of the metal substrate to form a mold with the metal substrate and define a cavity between the expendable, thin sheet metal shell and the surface of the metal substrate;
placing a hard particulate material within the cavity in close proximity to the surface and the expendable, thin sheet metal shell;
placing a metallic brazing material in communication with the cavity;
heating the metallic brazing material to a temperature above a melting point of the metallic brazing material and holding the temperature for a time sufficient for the metallic brazing material to infiltrate the hard particulate material in molten form and contact the surface of the metal substrate and the expendable, thin sheet metal shell with the expendable, thin sheet metal shell and the metal substrate containing the molten metal inside the mold; and
cooling the metallic brazing material to solidify the metallic brazing material and bond the hard particulate material to the metal substrate and the expendable, thin sheet metal shell to form a wear resistant composite coating on the surface of the metal substrate; and wherein the solidified metallic brazen material and the hard particulate material create a wear resistant composite coating on the surface, the wear resistant composite coating being in contact with and bonded to the surface of the substrate and the expendable thin, sheet metal shell.

2. The method of claim 1 , wherein the expendable, thin sheet metal shell has an opening to an exterior of the expendable, thin sheet metal shell, and a reservoir is connected to the expendable, thin sheet metal shell and positioned outside the cavity in communication with the opening, and wherein the metallic brazing material is placed within the reservoir in communication with the cavity.

3. The method of claim 2 , wherein the reservoir is integrally formed with the expendable, thin sheet metal shell.

4. The method of claim 1 , wherein the expendable, thin sheet metal shell comprises a conformal band extending around a periphery of the expendable, thin sheet metal shell, and connecting the expendable, thin sheet metal shell to the metal substrate comprises welding or brazing the conformal band to the surface of the metal substrate such that the conformal band is in surface-to-surface contact with a portion of the surface of the metal substrate around the entire conformal band to create a fluid-tight joint.

5. The method of claim 1 wherein the expendable, thin sheet metal shell comprises a conformal band extending around a periphery of the expendable, thin sheet metal shell, and connecting the expendable, thin sheet metal shell to the metal substrate comprises welding or brazing the conformal band to the surface of the metal substrate, such that the conformal band is in surface-to-surface contact with a portion of the surface of the metal substrate around the entire conformal band.

6. The method of claim 1 wherein the expendable, thin sheet metal shell comprises a front piece having a front flange extending transversely from a back edge of the front piece and a back piece having a back flange extending transversely from a front edge of the back piece, wherein the method comprises joining the front piece and the back piece together to form the expendable, thin sheet metal shell by welding or brazing the front flange to the back flange.

7. The method of claim 1 wherein the hard particulate material comprises tungsten carbide, and the metallic brazing material comprises Ni—Cr—Si—B brazing alloy, and wherein the metallic brazing material is heated to a temperature of approximately 2050° F. for a time of approximately 30 to 60 minutes.

8. The method of claim 1 comprising forming the expendable, thin sheet metal shell by (a) welding or brazing pieces of sheet metal together or (b) bending sheet metal in a particular configuration.

9. The method of claim 1 wherein the expendable, thin sheet metal shell thickness is substantially less than the nominal thickness of the metal substrate, and/or has a thickness in the range of 16 Ga to 10 Ga.

10. The method of claim 1 wherein the expendable, thin sheet metal shell weighs two percent or less of the weight of the metal substrate.

11. The method of claim 1 wherein the metal substrate is formed with a reduced thickness portion, and the expendable, thin sheet metal shell is connected to the metal substrate adjacent the reduced thickness portion to enclose and form the cavity with only the reduced thickness portion of the metal substrate.

12. The method of claim 1 wherein the metal substrate is formed by a sand casting process.

13. The method of claim 1 wherein the surface of the metal substrate has multiple separate regions facing in multiple different orientations, the expendable, thin sheet metal shell overlies each of the regions to define the cavity.

14. The method of claim 1 wherein the shell at least partially surrounds the metal substrate to define the cavity.

15. The method of claim 1 including forming the metal substrate with a configuration for mounting to an excavating bucket and digging in the ground.

16. The method of claim 1 wherein the connected expendable, thin sheet metal shell and the metal substrate forming a mold are cooperatively configured to contain the hard particulate material and the metallic brazing material during infiltration of the hard particulate material.

17. A method for making a wear part for earth engaging equipment comprising:
welding or brazing sheet metal shell to a surface of a substrate to define a cavity between the sheet metal shell and the surface and form a mold with the substrate;
placing a hard material within the cavity;
placing a metallic brazing material in communication with the cavity;
heating the metallic brazing material to a temperature above a melting point of the metallic brazing material and holding the temperature for a time sufficient for the metallic brazing material to infiltrate the hard material and contact the surface of the substrate in molten form, wherein the hard material and the melted metallic brazing material are contained by the mold formed by connecting the sheet metal shell to the substrate; and
cooling the metallic brazing material to solidify the metallic brazing material and bond the hard material to the surface of the substrate; and wherein the solidified metallic brazen material and the hard material create a wear resistant composite coating on the surface, the wear resistant composite coating being in contact with and bonded to the surface of the substrate and the sheet metal shell.

18. The method of claim 17 wherein welding or brazing the sheet metal shell to the surface of the substrate forms a mold with the substrate, the substrate and the sheet metal shell being cooperatively configured to contain the hard material and the metallic brazing material during infiltration of the hard material.

19. The method of claim 17 , wherein the sheet metal shell has an opening to an exterior of the sheet metal shell and a reservoir is connected to the sheet metal shell and positioned outside the cavity in communication with the opening, and wherein the metallic brazing material is placed within the reservoir to be in communication with the cavity.

20.

Assignees

• Esco Corp
• Esco Group Llc

Inventors

• Churchill Robin K

Classifications

• E21C35/183 Primary

  with inserts or layers of wear-resisting material {(drill bits with wear-resistant parts E21B10/46)} · CPC title

• B05D3/02

  by baking {(B05D3/04 takes precedence)} · CPC title

• B32B15/04

  comprising metal as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042)} · CPC title

• B05D5/00

  Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures · CPC title

• B23K31/02

  relating to soldering or welding · CPC title