# US 10,442,055 B2 · Lubricated mechanical polishing

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,442,055 B2
- Document ID: US10442055B2
- Status: Granted
- Kind: B2
- Application number: 15/530,575
- Filed: 2017-01-31
- Published: 2017-08-24
- Granted: 2019-10-15
- Earliest claimed: 2016-02-18
- Assignees: Iowa State University Research Foundation, Inc.
- Applicants: Iowa State University Research Foundation, Inc.
- Inventors: Ludovico Cademartiri; Briane Caroline Montoya
- Web page: https://patentgrep.com/patent/US10442055B2

## CPC

- B24B 37/044: {characterised by the composition of the lapping agent}
- C09K 3/1436: {Composite particles, e.g. coated particles}
- C09K 3/1472: {Non-aqueous liquid suspensions}
- C10M 125/10: Metal oxides, hydroxides, carbonates or bicarbonates
- C10M 2201/062: Oxides; Hydroxides; Carbonates or bicarbonates
- C10N 2020/06: Particles of special shape or size
- C10N 2040/22: with essential removal of material {, e.g. cutting, grinding or drilling}
- C10N 2040/25: Internal-combustion engines
- C10N 2050/015: {Dispersions of solid lubricants}
- C10N 2080/00: Special pretreatment of the material to be lubricated, e.g. phosphatising or chromatising of a metal
- B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C10M: LUBRICATING COMPOSITIONS (well drilling compositions C09K8/02); USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION (mould release, i.e. separating, agents for metals B22C3/00, for plastics or substances in a plastic state, in general B29C33/56, for glass C03B40/02; textile lubricating compositions D06M11/00, D06M13/00, D06M15/00; immersion oils for microscopy G02B21/33)
- C10N: INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS

## Abstract

A lubricated mechanical polishing (LMP) process is provided that uses hard nanoparticles of less than 5 nm diameter dispersed in a fluid lubricant as a polishing slurry to produce an ultra-smooth surface on a hard metallic or non-metallic substrate with a sub-nanometer surface roughness substantially less than that produced by silica chemical mechanical polishing.

## Claims

### Claim 1

A method of producing an ultra-smooth surface on a substrate, comprising dispersing hard nanoparticles having a hardness greater than 7 Mohs and a diameter dimension less than 5 nm in a hydrophobic organic fluid lubricant to form a polishing slurry and mechanically polishing the substrate using the slurry without chemical etching of the substrate to obtain an RMS surface roughness of about 3 A to about 5 A.

### Claim 2 (depends on 1)

The method of claim 1 wherein the hard nanoparticles comprise metal oxide nanoparticles.

### Claim 3 (depends on 2)

The method of claim 2 wherein the hard metal oxide nanoparticles comprise zirconium oxide.

### Claim 4 (depends on 1)

The method of claim 1 wherein the nanoparticles are functionalized with a ligand.

### Claim 5 (depends on 1)

The method of claim 1 wherein the hard nanoparticles are present in an amount of about 0.5 to about 2 weight % of the polishing slurry.

### Claim 6 (depends on 1)

The method of claim 1 wherein the lubricant is a motor oil.

### Claim 7 (depends on 1)

The method of claim 1 wherein the substrate is comprises a metal or alloy.

### Claim 8 (depends on 1)

The method of claim 1 wherein the substrate comprises a metal carbide or metal nitride.

### Claim 9 (depends on 1)

A metal or alloy substrate having a sub-nanometer RMS surface roughness of about 3 to about 5 Angstroms produced by the method of claim 1.

### Claim 10 (depends on 9)

The substrate of claim 9, which is a steel or a metal carbide.

### Claim 11

A method of producing an ultra-smooth surface on a substrate, comprising dispersing hard colloidal zirconium oxide nanoparticles having a diameter less than 5 nm in a motor oil to form a polishing slurry and mechanically polishing the substrate using the slurry without chemical etching of the substrate to achieve a sub-nanometer RMS surface roughness of about 3 A to about 5 A on the substrate.

### Claim 12 (depends on 11)

The method of claim 11 wherein the nanoparticles are functionalized with a ligand.

### Claim 13 (depends on 11)

The method of claim 11 wherein the motor oil is SAE 20 motor oil.