# US 5,341,719 A · Multi-layer composite gun barrel

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- Number: US 5,341,719 A
- Document ID: US5341719A
- Status: Granted
- Kind: A
- Application number: 07/990,107
- Filed: 1992-12-14
- Granted: 1994-08-30
- Earliest claimed: 1992-12-14
- Assignees: General Electric Company
- Inventors: Stephen J. Bullis; David P. Perrin; Peter C. Wolff
- Web page: https://patentgrep.com/patent/US5341719A

## CPC

- B21C 23/22: Making metal-coated products; Making products from two or more metals
- F41A 21/02: Composite barrels, i.e. barrels having multiple layers, e.g. of different materials
- B21C: MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE

## Abstract

A multi-layer composite gun barrel has an integral metal alloy jacket portion, forming the exterior cylinder of the entire barrel, with a forebarrel interior liner cylinder substantially bonded within the jacket portion, and an unbonded breech portion liner, made from a high melting temperature refractory metal alloy able to resist erosion by hot gun gases in the barrel breech area.

## Claims

### Claim 1

A gun barrel comprising a full-length jacket portion of a first alloy, having a multi-layer forebarrel portion wherein the jacket portion is substantially metallurgically bonded to a relatively thick liner portion formed of a second alloy, coextruded within the jacket portion to have a highly-concentric tubular interface, and with an interface diameter D.sub.i relatively greater than the diameter of the barrel bore.

### Claim 2 (depends on 1)

The gun barrel of claim 1, wherein the jacket portion alloy is selected to have a relatively low coefficient of temperature expansion with respect to the coefficient of temperature expansion of the material of the liner portion.

### Claim 3 (depends on 2)

The gun barrel of claim 2, wherein the liner portion alloy is selected to have a relatively high degree of hot gas erosion resistance with respect to the hot gas erosion resistance of the material of the jacket portion.

### Claim 4 (depends on 3)

The gun barrel of claim 3, wherein at least one of the first and second alloys is an alloy having a base of at least one selected one or iron, nickel and cobalt.

### Claim 5 (depends on 3)

The gun barrel of claim 3, wherein both of the first and second alloys are alloys having a base of at least one selected one of iron, nickel and cobalt.

### Claim 6 (depends on 1)

The gun barrel of claim 1, further comprising an unbonded breech boreliner in the breech end of the barrel jacket portion, enclosing at least a portion of a firing chamber therein and extending forward from said chamber toward the muzzle.

### Claim 7 (depends on 6)

The gun barrel of claim 6, wherein the exterior surface of the breech boreliner portion has an average diameter greater than the interface diameter D.sub.i between the liner and jacket portions of the barrel foreportion.

### Claim 8 (depends on 6)

The gun barrel of claim 6, wherein the boreliner portion has a bore length L.sub.b of less than one-quarter of the total length L of the barrel.

### Claim 9 (depends on 6)

The gun barrel of claim 6, wherein the breech boreliner is formed of a third alloy.

### Claim 10 (depends on 9)

The gun barrel of claim 9, wherein the third alloy is a refractory metal having a higher resistance than either of the first and second alloys to erosion by hot gun gases.