# US 11,028,466 B2 · Unleaded free-cutting brass alloys with excellent castability, method for producing the same, and application thereof

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

- Number: US 11,028,466 B2
- Document ID: US11028466B2
- Status: Granted
- Kind: B2
- Application number: 16/070,559
- Filed: 2017-01-12
- Published: 2019-02-07
- Granted: 2021-06-08
- Earliest claimed: 2016-01-21
- Assignees: Fortune Mfg. Co., Ltd.
- Applicants: Fortune Manufacturing Co., Ltd.
- Inventors: Chin-Lung Chen; Jhewn-Kuang Chen; Ci-Jie Hung
- Web page: https://patentgrep.com/patent/US11028466B2

## CPC

- C22C 9/04: with zinc as the next major constituent
- B22D 21/025: {Casting heavy metals with high melting point, i.e. 1000 - 1600 degrees C, e.g. Co 1490 degrees C, Ni 1450 degrees C, Mn 1240 degrees C, Cu 1083 degrees C}
- C22C 1/03: using master alloys
- C22F 1/08: of copper or alloys based thereon
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22)
- C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass, C23F17/00)

## Abstract

The present invention is directed to an unleaded free cutting brass alloy with excellent machinability, leak-tightness, reca stability, and mechanical properties, wherein the brass alloy comprises 65 to 75 weight % of copper, 22.5 to 32.5 weight % of zinc, 0.5 to 2.0 weight % of silicon, and other unavoidable impurities; wherein the total content of copper and zinc in the brass alloy is 97.5 weight % or more.

## Claims

### Claim 1

An unleaded free-cutting brass alloy, comprising:
copper: 68 to 75 weight %,
zinc: 22.5 to <30 weight %,
silicon: 1.0 to 2.0 weight %,
at least one element selected from the group consisting of 0.01 to 0.8 weight % of nickel and 0.01 to 0.55 weight % of antimony, and
unavoidable impurities,
wherein the total content of copper and zinc in the brass alloy is 97.5 weight % or more, and
wherein the γ-phase of the brass alloy is uniformly distributed between phase boundaries of the α-phase and the β-phase of the brass alloy in a granular shape.

### Claim 2 (depends on 1)

The brass alloy according to claim 1, further comprising at least one element selected from the group consisting of 0.01 to 1.0 weight % of aluminum, 0.01 to 0.55 weight % of tin, 0.01 to 0.55 weight % of manganese, and 0.001 to 0.1 weight % of boron.

### Claim 3 (depends on 2)

The brass alloy according to claim 2, comprising 0.2 to 0.5 weight % of aluminum.

### Claim 4 (depends on 2)

The brass alloy according to claim 2, comprising 0.01 to 0.2 weight % of tin.

### Claim 5 (depends on 2)

The brass alloy according to claim 2, comprising 0.01 to 0.25 weight % of manganese.

### Claim 6 (depends on 2)

The brass alloy according to claim 2, comprising 0.001 to 0.05 weight % of boron.

### Claim 7 (depends on 1)

The brass alloy according to claim 1, wherein the brass alloy comprises 1.1 to 1.35 weight % of silicon.

### Claim 8 (depends on 1)

The brass alloy according to claim 1, comprising 0.01 to 0.55 weight % of nickel.

### Claim 9 (depends on 1)

The brass alloy according to claim 1, comprising 0.1 to 0.45 weight % of antimony.

### Claim 10 (depends on 1)

An unleaded brass alloy casting product, comprising a brass alloy according to claim 1.

### Claim 11 (depends on 10)

The unleaded brass alloy casting product according to claim 10, comprising a valve, a piping part, or a filter.

### Claim 12 (depends on 10)

The unleaded brass alloy casting product according to claim 10, comprising a ball valve, a gate valve, a check valve, a gate valve with or without a lifting rod, a butterfly valve, or a Y-strainer.

### Claim 13 (depends on 10)

The unleaded brass alloy casting product according to claim 10, wherein the brass alloy does not leak under a pressure of 900 psi or higher.

### Claim 14 (depends on 10)

The unleaded brass alloy casting product according to claim 10, wherein the tensile strength of the brass alloy is 280 MPa or higher.

### Claim 15 (depends on 10)

The unleaded brass alloy casting product according to claim 10, wherein the fracture elongation of the brass alloy is 8% or more.

### Claim 16 (depends on 1)

A casting process comprising a step of pouring a melt of a brass alloy according to claim 1 into a green sand mold, a furan mold, or a metal mold to form a casting.

### Claim 17 (depends on 16)

The casting process according to claim 16, wherein the pouring step is conducted at a temperature from 930 to 1200° C.

### Claim 18 (depends on 16)

The casting process according to claim 16, wherein the casting is subjected to a machining step to produce a machined workpiece and turning scraps thereof.

### Claim 19 (depends on 18)

The casting process according to claim 18, wherein the melt of the brass alloy further comprises a re-melt from the machined workpiece or turning scraps thereof produced by the machining step of claim 18.