# US 8,771,789 B2 · Method for producing melt supply pipe for aluminum die casting

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- Number: US 8,771,789 B2
- Document ID: US8771789B2
- Status: Granted
- Kind: B2
- Application number: 13/675,830
- Filed: 2012-11-13
- Published: 2013-06-06
- Granted: 2014-07-08
- Earliest claimed: 2005-12-02
- Assignees: Toshiba Kikai Kabushiki Kaisha
- Applicants: Toshiba Kikai Kabushiki Kaisha
- Inventors: Jun Masuda; Ryosuke Fujimoto
- Web page: https://patentgrep.com/patent/US8771789B2

## CPC

- B23P 17/00: Metal-working operations, not covered by a single other subclass or another group in this subclass
- C21D 8/10: during manufacturing of tubular bodies
- Y10T 29/49885: with coating before or during assembling
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (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; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Methods are disclosed for producing melt supply pipes. In one illustrative implementation, there is provided a method for producing a melt supply pipe, composed of an inner ceramic pipe and an outer steel pipe fitted to the inner pipe, the melt supply pipe directed to connecting a melting furnace and a plunger sleeve of a die casting machine. Moreover, the method may include forming a Ni alloy layer over the inner circumferential surface of the outer steel pipe, burying the outer pipe in and bonding the surface of the Ni alloy layer to TiC particles, and fitting the inner ceramic pipe into the outer pipe with the TiC particles bonded to the inner circumferential surface.

## Claims

### Claim 1

A method for producing a melt supply pipe, composed of an inner ceramic pipe and an outer steel pipe fitted to the inner pipe, for connecting a melting furnace and a plunger sleeve of a die casting machine, comprising the steps of:
forming a Ni alloy layer over the inner circumferential surface of the outer steel pipe;
burying the outer pipe with the Ni alloy layer in TiC powder, and heating the pipe and the powder under vacuum in a vacuum heating oven to a temperature at which a liquid phase is generated from the Ni alloy, thereby bonding the TiC particles to the surface of the Ni alloy layer; and
fitting the inner ceramic pipe into the outer pipe with the TiC particles bonded to the inner circumferential surface, thereby assembling the melt supply pipe.

### Claim 2 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein after bonding the TiC particles to the inner circumferential surface of the outer pipe, a slurry of a mixture of a binder and powder comprising at least one of boron nitride (BN), alumina (Al2O3), zirconia (ZrO2) and silicon nitride (Si3N4) is applied to the inner circumferential surface of the outer pipe, followed by burning of the powder into the inner circumferential surface.

### Claim 3 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein one end of the inner ceramic pipe is inserted into the outer steel pipe with a pair of fibrous sheet members, composed of an inorganic material having the property of expanding by heating, placed on the inner circumferential surface of the outer pipe at its both ends such that each sheet member extends over the entire circumference, and, before inserting the other end of the inner pipe into the outer pipe, a spherical or particulate ceramic filler is filled into the gap formed between the inner and outer pipes and defined by one of the sheet members.

### Claim 4 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein the TiC particles have an average particle diameter of about 10 to about 500 μm.

### Claim 5 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein the TiC particles are bonded to the Ni alloy layer in such a state that the particles are not fully covered with the Ni alloy layer but partly protrude from the Ni alloy layer.

### Claim 6 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein the Ni alloy, in addition to Ni, comprises about 2.6 to about 3.2% of B, about 18 to about 28% of Mo, about 3.6 to about 5.2% of Si and about 0.05 to about 0.22% of C.

### Claim 7 (depends on 1)

The method for producing a melt supply pipe according to claim 1, wherein gaps in the TiC particles are filled in with powder comprising at least one of boron nitride (BN), alumina (Al2O3), zirconia (ZrO2) and silicon nitride (Si3N4).

### Claim 8 (depends on 2)

The method for producing a melt supply pipe according to claim 2, wherein one end of the inner ceramic pipe is inserted into the outer steel pipe with a pair of fibrous sheet members, composed of an inorganic material having the property of expanding by heating, placed on the inner circumferential surface of the outer pipe at its both ends such that each sheet member extends over the entire circumference, and, before inserting the other end of the inner pipe into the outer pipe, a spherical or particulate ceramic filler is filled into the gap formed between the inner and outer pipes and defined by one of the sheet members.

### Claim 9 (depends on 2)

The method for producing a melt supply pipe according to claim 2, wherein the TiC particles have an average particle diameter of about 10 to about 500 μm.

### Claim 10 (depends on 2)

The method for producing a melt supply pipe according to claim 2, wherein the TiC particles are bonded to the Ni alloy layer in such a state that the particles are not fully covered with the Ni alloy layer but partly protrude from the Ni alloy layer.

### Claim 11 (depends on 2)

The method for producing a melt supply pipe according to claim 2, wherein the Ni alloy, in addition to Ni, comprises about 2.6 to about 3.2% of B, about 18 to about 28% of Mo, about 3.6 to about 5.2% of Si and about 0.05 to about 0.22% of C.

### Claim 12 (depends on 2)

The method for producing a melt supply pipe according to claim 2, wherein gaps in the TiC particles are filled in with powder comprising at least one of boron nitride (BN), alumina (Al2O3), zirconia (ZrO2) and silicon nitride (Si3N4).

### Claim 13 (depends on 3)

The method for producing a melt supply pipe according to claim 3, wherein the TiC particles have an average particle diameter of about 10 to about 500 μm.

### Claim 14 (depends on 3)

The method for producing a melt supply pipe according to claim 3, wherein the TiC particles are bonded to the Ni alloy layer in such a state that the particles are not fully covered with the Ni alloy layer but partly protrude from the Ni alloy layer.

### Claim 15 (depends on 3)

The method for producing a melt supply pipe according to claim 3, wherein the Ni alloy, in addition to Ni, comprises about 2.6 to about 3.2% of B, about 18 to about 28% of Mo, about 3.6 to about 5.2% of Si and about 0.05 to about 0.22% of C.

### Claim 16 (depends on 3)

The method for producing a melt supply pipe according to claim 3, wherein gaps in the TiC particles are filled in with powder comprising at least one of boron nitride (BN), alumina (Al2O3), zirconia (ZrO2) and silicon nitride (Si3N4).

### Claim 17 (depends on 4)

The method for producing a melt supply pipe according to claim 4, wherein the TiC particles are bonded to the Ni alloy layer in such a state that the particles are not fully covered with the Ni alloy layer but partly protrude from the Ni alloy layer.

### Claim 18 (depends on 4)

The method for producing a melt supply pipe according to claim 4, wherein the Ni alloy, in addition to Ni, comprises about 2.6 to about 3.2% of B, about 18 to about 28% of Mo, about 3.6 to about 5.2% of Si and about 0.05 to about 0.22% of C.

### Claim 19 (depends on 4)

The method for producing a melt supply pipe according to claim 4, wherein gaps in the TiC particles are filled in with powder comprising at least one of boron nitride (BN), alumina (Al2O3), zirconia (ZrO2) and silicon nitride (Si3N4).

### Claim 20 (depends on 5)

The method for producing a melt supply pipe according to claim 5, wherein the Ni alloy, in addition to Ni, comprises about 2.6 to about 3.2% of B, about 18 to about 28% of Mo, about 3.6 to about 5.2% of Si and about 0.05 to about 0.22% of C.