Functionally graded carbides

Patent metadata

Field	Value
Publication number	US-10501376-B2
Application number	US-201615545248-A
Country	US
Kind code	B2
Filing date	Jan 22, 2016
Priority date	Jan 22, 2015
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A functionally graded carbide body (400) can include a group 5 metal carbide substrate having a bulk composition region (410) that contains at least 70 wt % of a rhombohedral ζ-phase carbide. A γ-phase-rich region (420) having a γ-phase-rich composition can be at a surface (430) of the substrate, and a phase composition gradient region (440) can transition from the γ-phase-rich composition region at the surface to the bulk composition region at a gradient depth (450) below the surface.

First claim

What is claimed is:

1. A functionally graded carbide body of a group 5 metal carbide, comprising:
a bulk composition region comprising at least 70 wt % of a rhombohedral ζ-phase carbide of the group 5 metal carbide;
a γ-phase-rich region having a γ-phase-rich composition at a surface of the carbide body; and
a phase composition gradient region transitioning from the γ-phase-rich composition region to the bulk composition region at a gradient depth below the surface.

2. The functionally graded carbide body of claim 1 , wherein the γ-phase-rich composition region is from 70 wt % to 100 wt % γ-phase.

3. The functionally graded carbide body of claim 1 , wherein the phase composition gradient region transitions substantially continuously from the γ-phase-rich composition region to the bulk composition region.

4. The functionally graded carbide body of claim 1 , wherein the γ-phase-rich composition region has a substantially uniform carbon to group 5 metal atomic ratio to a first depth from the surface, and then transitions continuously to the bulk composition region at the gradient depth.

5. The functionally graded carbide body of claim 4 , wherein the first depth is from 2 micrometers to 30 micrometers.

6. The functionally graded carbide body of claim 1 , wherein the gradient depth is from 5 micrometers to 50 micrometers.

7. The functionally graded carbide body of claim 1 , wherein the carbide body is a substantially pure carbide.

8. The functionally graded carbide body of claim 1 , wherein the carbide body has a surface hardness HK0.1 of about 10 GPa to about 25 GPa.

9. The functionally graded carbide body of claim 1 , wherein the carbide body has a bulk fracture toughness of about 10 MPa√m to about 15 MPa√m.

10. The functionally graded carbide body of claim 1 , wherein the carbide body has a residual compressive stress at the surface.

11. The functionally graded carbide body of claim 1 , wherein the group 5 metal is tantalum.

12. The functionally graded carbide body of claim 11 , wherein the γ-phase-rich composition region has a carbon to tantalum atomic ratio from about 0.78 to about 1.0.

13. The functionally graded carbide body of claim 1 , wherein the group 5 metal is niobium.

14. The functionally graded carbide body of claim 13 , wherein the γ-phase-rich composition region has a carbon to niobium atomic ratio from about 0.73 to about 1.0.

15. The functionally graded carbide body of claim 1 , wherein the group 5 metal is vanadium.

16. The functionally graded carbide body of claim 15 , wherein the γ-phase-rich composition region has a carbon to vanadium atomic ratio from about 0.7 to about 0.88.

Assignees

• Univ Utah Res Found

Inventors

• Shetty Dinesh
• Cutler Raymond
• Sygnatowicz Michael M

Classifications

• C04B35/5607 Primary

  based on refractory metal carbides · CPC title

• C22C29/06

  based on carbides, but not containing other metal compounds · CPC title

• B22F2207/01

  Composition gradients · 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

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title