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US 8,506,730 B2Granted
Copper/zinc alloys having low levels of lead and good machinability
AssigneeMitsubishi Shindoh Co., Ltd.
InventorKeiichiro Oishi
Life of this patent
Estimating the term…
Abstract
The free-cutting copper alloy according to the present invention contains a greatly reduced amount of lead in comparison with conventional free-cutting copper alloys, but provides industrially satisfactory machinability. The free-cutting alloys comprise 69 to 79 percent, by weight, of copper, 2.0 to 4.0 percent, by weight, of silicon, 0.02 to 0.4 percent, by weight, of lead, and the remaining percent, by weight, of zinc.
Claims19
A free-cutting copper-silicon-zinc alloy, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein
- an extruded round test piece of the alloy having a circumferential surface, when cut on the circumferential surface by a lathe provided with a point nose straight tool at a rake angle of −8 degrees at a cutting rate of 50 m/min, a cutting depth of 1.5 mm and a feed rate of 0.11 min/rev, yields chips having one or more shapes selected from the group consisting of an arc shape and a needle shape.
3 more elements
A free-cutting copper-silicon-zinc alloy, consisting essentially of:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a gamma phase formed in the matrix, wherein the gamma phase serves to improve machinability of the alloy.
4 more elements
A free-cutting copper-silicon-zinc alloy, consisting essentially of:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein
- an extruded round test piece of the alloy having a circumferential surface, when cut on the circumferential surface by a lathe provided with a point nose straight tool at a rake angle of −8 degrees at a cutting rate of 50 m/min, a cutting depth of 1.5 mm and a feed rate of 0.11 mm/rev, yields chips having one or more shapes selected from the group consisting of an arc shape and a needle shape.
3 more elements
A free-cutting copper-silicon-zinc alloy containing no tin, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a gamma phase formed in the matrix, wherein the gamma phase serves to improve machinability of the alloy.
4 more elements
A free-cutting copper-silicon-zinc alloy containing no tin, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein
- an extruded round test piece of the alloy having a circumferential surface, when cut on the circumferential surface by a lathe provided with a point nose straight tool at a rake angle of −8 degrees at a cutting rate of 50 m/min, a cutting depth of 1.5 mm and a feed rate of 0.11 min/rev, yields chips having one or more shapes selected from the group consisting of an arc shape and a needle shape.
3 more elements
A free-cutting copper-silicon-zinc alloy, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a kappa phase, or a kappa phase and a gamma phase, formed in the matrix,
- wherein the gamma phase and the kappa phase serve to improve machinability of the alloy.
5 more elements
A free-cutting copper-silicon-zinc alloy, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a gamma phase and a kappa phase, wherein the gamma phase and the kappa phase are formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a kappa phase, or a kappa phase and a gamma phase, wherein the kappa phase is formed in the matrix, and the gamma phase is formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy containing no tin, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a kappa phase, or a kappa phase and a gamma phase, wherein the kappa phase is formed in the matrix, and the gamma phase is formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy, consisting essentially of:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a kappa phase, or a kappa phase and a gamma phase, wherein the kappa phase is formed in the matrix and the gamma phase is formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy, consisting of:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a gamma phase formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy, consisting of:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a kappa phase, or a kappa phase and a gamma phase, wherein the kappa phase is formed in the matrix and the gamma phase is formed in the matrix.
4 more elements
A free-cutting copper-silicon-zinc alloy, comprising:
- 69 to 79 percent, by weight, of copper;
- 2.0 to 4.0 percent, by weight, of silicon;
- 0.02 to 0.4 percent, by weight, of lead;
- and a remaining percentage, by weight, of zinc;
- wherein the copper-silicon-zinc alloy includes
- (a) a matrix comprising an alpha phase, and
- (b) a gamma phase formed in the matrix, wherein the gamma phase serves to improve machinability of the alloy, and
- wherein
- an extruded round test piece of the alloy having a circumferential surface, when cut on the circumferential surface by a lathe provided with a point nose straight tool at a rake angle of −8 degrees at a cutting rate of 50 m/min, a cutting depth of 1.5 mm and a feed rate of 0.11 mm/rev, yields chips having one or more shapes selected from the group consisting of an arc shape and a needle shape.
6 more elements
Dependencies are inferred from the claim text.