Wear resistant material and system and method of creating a wear resistant material
A system and method of forming a wear resistant composite material includes placing a porous wear resistant filler material in a mold cavity and infiltrating the filler material with a matrix material by heating to a temperature sufficient to melt the matrix material, then cooling the assembly to form a wear resistant composite material. The system and method can be used to form the wear resistant composite material on the surface of a substrate, such as a part for excavating equipment or other mechanical part. One suitable matrix material may be any of a variety of ductile iron alloys.
1. A point for an excavating tooth having a working portion to contact the ground during operation of the earthmoving equipment, the working portion including a steel substrate having oppositely-facing surfaces extending to a distal end, a cavity formed in each of the oppositely-facing surfaces extending rearward from the distal end, a composite coating filling each of the cavities to overlay those portions of the oppositely-facing surfaces and the distal end that are within each of the cavities, and a shell secured to the substrate rearward of each of the cavities to define an outer shape of the composite coating, the composite coating comprising a porous wear resistant material infiltrated by a matrix material wherein the matrix material is principally ductile iron and bonds the composite coating to the working portion and the shell.
2. The point of claim 1 , wherein the matrix material has a composition comprising, in weight percent, approximately 3.0-4.0% carbon, approximately 1.8-2.8% silicon, approximately 0.1-1.0% manganese, approximately 0.01-0.03% sulfur, and approximately 0.01-0.1% phosphorous, with the balance being iron and incidental elements and impurities.
3. The point of claim 2 , wherein the composition of the matrix material further comprises up to 37 wt. % nickel.
4. The point of claim 2 , wherein the composition of the matrix material further comprises up to 5.5 wt. % chromium.
5. The point of claim 1 , wherein the composition of the matrix material further comprises up to 5.5 wt. % silicon.
6. The point of claim 1 , wherein the porous wear resistant material is a particulate material, and the matrix material bonds the wear resistant material together.
7. The point of claim 1 , wherein the wear resistant material comprises one or more materials selected from the group consisting of: carbides, nitrides, borides, silicides, intermetallic compounds of transition metals, and combinations thereof.
8. The point of claim 1 , wherein the steel substrate has a plurality of protrusions connected to the working portion and extending outwardly from the working portion, and wherein the protrusions are embedded within the composite coating.
9. The point of claim 8 , wherein the plurality of protrusions comprise a plurality of rib members symmetrically distributed on the working portion.
10. The point of claim 1 , wherein the composite coating has a thickness that is greater than a thickness of the substrate.
11. The point of claim 1 , wherein the composite coating has a thickness of at least 7.5 inches.
12. The point of claim 1 , wherein the shell has a conformal band in contact with the working portion rearward of the cavities.
13. The point of claim 12 , wherein the shell is connected to the steel substrate by welding or brazing rearward of the cavities.
14. The point of claim 1 where the wear resistant material within the cavity is primarily particles less than 1 mm in size.