# US 5,707,065 A · Sintered SIC mechanical seals having particular pore volume, shape, and diameter

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- Number: US 5,707,065 A
- Document ID: US5707065A
- Status: Granted
- Kind: A
- Application number: 08/764,272
- Filed: 1996-12-12
- Granted: 1998-01-13
- Earliest claimed: 1990-10-17
- Assignees: Ceramiques et Composites
- Inventors: Olivier Azema; Michel Bougoin
- Web page: https://patentgrep.com/patent/US5707065A

## CPC

- C04B 38/0061: {closed porosity}
- C04B 35/565: based on silicon carbide
- C04B 38/0051: {characterised by the pore size, pore shape or kind of porosity}
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

Mechanically strong and reduced friction porous silicon carbide sintered shaped articles, well adapted for the production, e.g., of leaktight mechanical packings and rotating bearing seals, have a total pore volume ranging from 4% to 18% thereof, the pores of which having an average diameter of the spherical closed pores ranging from 40 to 200 .mu.m.

## Claims

### Claim 1

A mechanical packing/seal which comprises a fixed ring member and a rotatable counter-ring member frictionally engaged therewith, at least one of said ring members comprising a porous silicon carbide sintered shaped article having a total pore volume ranging from 4% to 18% thereof, the pores of which being essentially closed, essentially spherical in shape and having an average diameter ranging from greater than 50 to 200 .mu.m.

### Claim 2 (depends on 1)

The mechanical packing/seal as defined by claim 1, the pores of said sintered shaped article having an average diameter ranging from greater than 50 to 150 .mu.m.

### Claim 3 (depends on 1)

The mechanical packing/seal as defined by claim 1, the pores of said sintered shaped article having an average diameter ranging from 60 to 200 .mu.m.

### Claim 4 (depends on 3)

The mechanical packing/seal as defined by claim 3, the pores of said sintered shaped article having an average diameter ranging from 60 to 150 .mu.m.

### Claim 5 (depends on 4)

The mechanical packing/seal as defined by claim 4, the pores of said sintered shaped article having an average diameter ranging from 60 to 100 .mu.m.

### Claim 6 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article having a total pore volume ranging from 5% to 15% thereof.

### Claim 7 (depends on 6)

The mechanical packing/seal as defined by claim 6, said sintered shaped article having a total pore volume ranging from 8% to 15% thereof.

### Claim 8 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article comprising .alpha.-SiC.

### Claim 9 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article comprising .beta.-SIC.

### Claim 10 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article comprising elemental carbon.

### Claim 11 (depends on 10)

The mechanical packing/seal as defined by claim 10, said sintered shaped article comprising graphitic carbon.

### Claim 12 (depends on 10)

The mechanical packing/seal as defined by claim 10, said sintered shaped article comprising up to 20 % by weight of elemental carbon.

### Claim 13 (depends on 12)

The mechanical packing/seal as defined by claim 12, said sintered shaped article comprising up to 10% by weight of elemental carbon.

### Claim 14 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article comprising a sintering additive.

### Claim 15 (depends on 1)

The mechanical packing/seal as defined by claim 1, said sintered shaped article having been produced from SiC particulates having a particle size ranging from 1 to 500 .mu.m.

### Claim 16 (depends on 15)

The mechanical packing/seal as defined by claim 15, said sintered shaped article having been produced from SiC particulates having a particle size ranging from 1 to 20 .mu.m.

### Claim 17

An organization which comprises at least two frictionally engaged face surfaces, at least one such face surface comprising a porous silicon carbide sintered shaped article having a total pore volume ranging from 4% to 18% thereof, the pores of which being essentially closed, essentially spherical in shape and having an average diameter ranging from greater than 50 to 200 .mu.m.

### Claim 18 (depends on 17)

The organization as defined by claim 17, the pores of said sintered shaped article having an average diameter ranging from greater than 50 to 150 .mu.m.

### Claim 19 (depends on 17)

The organization as defined by claim 17, the pores of said sintered shaped article having an average diameter ranging from 60 to 200 .mu.m.

### Claim 20 (depends on 17)

The organization as defined by claim 17, comprising a thrust block, or a bearing or slide face surface.