# US 5,350,004 A · Rigidized filler materials for metal matrix composites and precursors to supportive structural refractory molds

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- Number: US 5,350,004 A
- Document ID: US5350004A
- Status: Granted
- Kind: A
- Application number: 07/971,850
- Filed: 1993-01-08
- Granted: 1994-09-27
- Earliest claimed: 1993-01-08
- Assignees: Lanxide Technology Company, LP
- Inventors: Michael A. Rocazella; Kurt J. Becker; Michael K. Aghajanian
- Web page: https://patentgrep.com/patent/US5350004A

## CPC

- C04B 41/009: {characterised by the material treated}
- C04B 41/5155: {Aluminium}
- C04B 41/88: Metals
- C22C 1/1036: {starting from a melt}
- C22C 1/1063: {Gas reaction, e.g. lanxide}
- C04B 2111/00931: {Coated or infiltrated preforms, e.g. with molten metal}
- Y10T 428/12486: Laterally noncoextensive components [e.g., embedded, etc.]
- 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
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention relates to a novel process for forming metal matrix composite bodies. Specifically, in a particularly preferred embodiment for making metal matrix composite bodies by a spontaneous infiltration technique, an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere are in communication with a rigidized filler material or a rigidized preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the rigidized filler material or riigidized preform. A structural refractory material which holds the preform is made by forming a first precursor to the supportive structural refractory material and subsequently causing the precursor to become a rigid supportive structural member. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.

## Claims

### Claim 1

A method for making a metal matrix composite comprising:
providing at least one permeable mass of at least one filler;
rigidizing said at least one permeable mass to form at least one rigidized mass by (1) at least one process selected from the group consisting of (a) mixing at least one colloidal oxide having strengthening characteristics with said at least one permeable mass and (b) heating said at least one permeable mass to a sufficient temperature and holding at said temperature for a sufficient amount of time to at least partially sinter at least one of said at least one colloidal oxide having strengthening effects and said at least one filler and (2) at least partially surrounding said at least one permeable mass with at least one precursor to at least one supportive structural refractory material which contacts at least a portion of at least one exterior surface of said at least one permeable mass, causing said at least one precursor to at least one supportive structural refractory material to become at least one supportive structural refractory material; and
spontaneously infiltrating at least a portion of said at least one rigidized mass with at least one molten matrix metal.

### Claim 2 (depends on 1)

The method of claim 1, wherein said at least one colloidal oxide having strengthening effects and said at least one permeable mass are heated prior to being contacted with at least one molten matrix metal.

### Claim 3 (depends on 2)

The method of claim 2, wherein said heating results in an at least partially three-dimensionally interconnected at least one permeable mass.

### Claim 4 (depends on 2)

The method of claim 2, wherein said at least one colloidal oxide having strengthening effects comprises at least one of at least one colloidal alumina and at least one colloidal silica.

### Claim 5 (depends on 1)

The method of claim 1, wherein said at least one filler comprises at least one silicon carbide and said at least one silicon carbide is at least partially converted to at least one silicon oxide during said at least partially sintering.

### Claim 6 (depends on 1)

The method of claim 1, wherein said at least one supportive structural refractory material surrounds a majority of said at least one permeable mass.

### Claim 7 (depends on 6)

The method of claim 6, wherein said at least one supportive structural refractory material is formed by providing at least one precursor to said at least one supportive material on at least a portion of at least one exterior surface of sad at least one permeable mass and converting said at least one precursor into said at least one supportive material prior to contacting at least one molten matrix metal with said at least one permeable mass.

### Claim 8 (depends on 6)

The method of claim 6, wherein said at least one supportive structural refractory material comprises at least one material selected from the group consisting of steels, graphites, glass frits and colloidal oxides.

### Claim 9 (depends on 1)

The method of claim 1, wherein said permeable mass is rigidized by combining at least two of said at least one process and at least partially surrounding said at least one permeable mass with at least one supportive structural refractory material which contacts at least a portion of at least one exterior surface of said at least one permeable mass.

### Claim 10 (depends on 1)

The method of claim 1, wherein said infiltrating comprises spontaneous infiltration.

### Claim 11 (depends on 10)

The method of claim 10, wherein at least one infiltration enhancer precursor is provided to at least one of said at least one permeable mass, said at least one rigidized mass and said at least one molten matrix metal, and said at least one infiltration enhancer precursor is caused to react to form at least one infiltration enhancer in at least a portion of at least one said at least one permeable mass and said at least one rigidized mass.

### Claim 12 (depends on 11)

The method of claim 11, wherein said at least one infiltration enhancer precursor reacts with at least one infiltrating atmosphere.

### Claim 13 (depends on 12)

The method of claim 12, wherein said at least one infiltrating atmosphere is present for only a portion of the infiltrating process.

### Claim 14 (depends on 1)

The method of claim 1, wherein said at least one colloidal oxide is initially present in said at least one permeable mass in an amount of about 1-15 percent by weight.

### Claim 15 (depends on 1)

The method of claim 1, wherein said at least one permeable mass comprises at least one ceramic material.

### Claim 16 (depends on 1)

The method of claim 1, wherein said at least one matrix metal comprises aluminum.

### Claim 17

A method for making a metal matrix composite comprising:
providing at least one permeable mass comprising at least one filler;
at least partially surrounding said at lest one permeable mass with at least one precursor to at least one supportive structural refractory material which contacts at least a portion of at least one exterior surface of said at lest one permeable mass;
providing at least one matrix metal;
providing at least one material comprising at least one of at least one infiltration enhancer precursor and at least one infiltration enhancer to at least one of said at least one permeable mass and said at least one matrix metal;
providing at least one infiltrating atmosphere;
causing said at least one precursor to at least one supportive structural refractory material to become at least one supportive structural refractory material;
causing said at least one matrix metal to become molten; and
spontaneously infiltrating at least a portion of said at least one permeable mass.

### Claim 18 (depends on 17)

The method of claim 17, further comprising heating of said at least one permeable mass thereby resulting in an at least partially three-dimensionally interconnected at least one permeable mass.

### Claim 19

The method of clam 17, further comprising providing at least one colloidal oxide comprising at least one material selected from the group consisting of at least one colloidal alumina and at least one colloidal silica to said at least one permeable mass.

### Claim 20 (depends on 17)

A metal matrix composite body made according to claim 17.
