Abstract: Production methods for Ti—Al alloys may include: adding a flux including calcium oxide containing 35+wt. % calcium fluoride, to a melt starting material of Ti material and Al material and with 50+wt. % Al; introducing the fluxed melt starting material into a water-cooled copper crucible having a tapping port in the bottom, induction melting it inside the water-cooled copper crucible in at least a 1.33 Pa atmosphere; the flux, containing oxygen released from the melt starting material by the induction melting, is separated out by tapping the melt starting material, which was induction melted in the water-cooled copper crucible, downward from the tapping port; and when obtaining the Ti—Al alloy by casting the flux-removed melt starting material, the induction melting output is reduced to no more than 90% of that during melting and tapping is performed from the water-cooled crucible with the output in a reduced state.

Abstract: The objective of the present invention is to improve non-defective product yield by reducing shrinkage cavities inside small-diameter ingots, in a method for casting active metals. In this Ti—Al based alloy casting method for casting an ingot of Ti—Al based alloy by tapping molten metal from a tapping hole (5) provided in a bottom portion of a water-cooled copper crucible (2), in an induction melting furnace (3) employing said crucible (2), into a casting mold (4), the degree of vacuum inside the induction melting furnace (3) when the Ti—Al based alloy is being melted or cast is in a range of 80 to 700 Torr, and the Al concentration in the cast ingot is within ±1.0 mass % of a target value.

Abstract: A method includes the production of a primary ingot, the production of a secondary ingot, and the removal of a flux layer. A CaO—CaF2 flux in a content of 3-20 mass % and obtained by mixing 35-95 mass % of CaF2 with CaO is added to a Ti—Al alloy material including a total of at least 0.1 mass % of oxygen and at least 40 mass % of Al, and the resultant substance is melted by a melting method using a water-cooled copper container in an atmosphere having a pressure of 1.33 Pa or higher and held to produce the primary ingot. The primary ingot is continuously drawn downwards while being melted by a melting method using a bottomless water-cooled copper casting mould in an atmosphere having a pressure of 1.33 Pa or higher to produce the secondary ingot. The flux layer deposited on the surface of the secondary ingot is mechanically removed.

Abstract: Disclosed herein is a method for deoxidizing an Al—Nb—Ti alloy, which includes melting and holding an Al—Nb—Ti alloy containing from 50 to 75 mass % of Al, from 5 to 30 mass % of Nb, and 80 mass % or less in total of Al and Nb by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa to 2.67×105 Pa at a temperature of 1,900 K or more, thereby decreasing an oxygen content thereof. The Al—Nb—Ti alloy is prepared using an alloy material formed of an aluminum material, a niobium material and a titanium material and containing oxygen in a total amount of 0.5 mass % or more.

Abstract: A casting method of an active metal includes, in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible to cast an ingot of the active metal. In conducting the casting under a casting condition in which the ingot has a diameter (D) of 10 mm or more and a ratio (H/D) of an ingot height H to the ingot diameter D of 1.5 or more and a weight of the molten metal tapped in the casting is 200 kg or less, a temperature of the molten metal in the casting is set to be higher than the melting point of the active metal and a casting velocity V (mm/sec) is controlled to satisfy V?0.1H in relation with the ingot height H by adjusting an opening diameter of the tapping hole.

Abstract: A method includes the production of a primary ingot, the production of a secondary ingot, and the removal of a flux layer. A CaO—CaF2 flux in a content of 3-20 mass % and obtained by mixing 35-95 mass % of CaF2 with CaO is added to a Ti—Al alloy material including a total of at least 0.1 mass % of oxygen and at least 40 mass % of Al, and the resultant substance is melted by a melting method using a water-cooled copper container in an atmosphere having a pressure of 1.33 Pa or higher and held to produce the primary ingot. The primary ingot is continuously drawn downwards while being melted by a melting method using a bottomless water-cooled copper casting mould in an atmosphere having a pressure of 1.33 Pa or higher to produce the secondary ingot. The flux layer deposited on the surface of the secondary ingot is mechanically removed.

Abstract: A method for refining a titanium material, in which oxygen contained in a titanium material made of a pure titanium, a titanium alloy or an intermetallic compound containing titanium as one of main components is removed, the method includes: a first melting step of melting the titanium material under a noble gas atmosphere containing 5 to 70 vol % of hydrogen, thereby introducing hydrogen into a melt of the titanium material; and a second melting step of melting the titanium material into which hydrogen has been introduced in the first melting step under a noble gas atmosphere, thereby removing oxygen contained in the titanium material from the melt of the titanium material together with the hydrogen. Each of the first melting step and the second melting step is carried out at least once.

Abstract: A casting method of an active metal includes, in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible to cast an ingot of the active metal. In conducting the casting under a casting condition in which the ingot has a diameter (D) of 10 mm or more and a ratio (H/D) of an ingot height H to the ingot diameter D of 1.5 or more and a weight of the molten metal tapped in the casting is 200 kg or less, a temperature of the molten metal in the casting is set to be higher than the melting point of the active metal and a casting velocity V (mm/sec) is controlled to satisfy V?0.1H in relation with the ingot height H by adjusting an opening diameter of the tapping hole.

Abstract: Disclosed herein is a method for deoxidizing an Al—Nb—Ti alloy, which includes melting and holding an Al—Nb—Ti alloy containing from 50 to 75 mass % of Al, from 5 to 30 mass % of Nb, and 80 mass % or less in total of Al and Nb by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa to 2.67×105 Pa at a temperature of 1,900 K or more, thereby decreasing an oxygen content thereof. The Al—Nb—Ti alloy is prepared using an alloy material formed of an aluminum material, a niobium material and a titanium material and containing oxygen in a total amount of 0.5 mass % or more.

Abstract: A method for deoxidizing a Ti—Al alloy includes melting and holding a Ti—Al alloy containing 40 mass % or more of Al by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa or more, thereby decreasing an oxygen content in the Ti—Al alloy. The Ti—Al alloy is manufactured using an alloy material composed of a titanium material and an aluminum material. The alloy material contains oxygen in a total amount of 0.1 mass % or more.

Abstract: By controlling the temperature (TS) of a surface portion (11a) of an ingot (11) in a contact region (16) between a mold (2) and the ingot (11) and/or a passing heat flux (q) from the surface portion (11a) of the ingot (11) to the mold (2) in the contact region (16), the thickness (D) in the contact region (16) of a solidified shell (13) obtained by the solidification of molten metal (12) is brought into a predetermined range. Consequently, an ingot having a good casting surface state can be cast.

Abstract: Disclosed is a continuous casting method in which a melt obtained by melting titanium or a titanium alloy is poured into a bottomless mold and is drawn downward while being solidified, wherein: the surface of the melt in the mold is heated by horizontally moving a plasma torch over the surface of the melt; thermocouples are provided at a plurality of locations along the circumferential direction of the mold; if the temperature of the mold measured by one of the thermocouples is lower than a target temperature, then the output of the plasma torch is increased when the plasma torch comes close to the location where that thermocouple is installed; and if said temperature is higher than the target temperature, then the output of the plasma torch is decreased when the plasma torch comes close to the location where that thermocouple is installed.

Abstract: A continuous casting method in which a molten metal obtained by melting titanium or a titanium alloy is injected into a bottomless mold having a rectangular cross-section and withdrawn downward while being caused to solidify, wherein a plasma torch (7) is caused to rotate in the horizontal direction above the surface of the molten metal (12) in the mold (2), and a horizontally rotating flow is generated by electromagnetic stirring on at least the surface of the molten metal (12) in the mold (2). It is thereby possible to cast a slab in which the casting surface condition is excellent.

Abstract: A continuous casting method in which a molten metal obtained by melting titanium or a titanium alloy is injected into a bottomless mold having a rectangular cross-section and withdrawn downward while being caused to solidify, wherein a plasma torch (7) is caused to rotate in the horizontal direction above the surface of the molten metal (12) in the mold (2), and a horizontally rotating flow is generated by electromagnetic stirring on at least the surface of the molten metal (12) in the mold (2). It is thereby possible to cast a slab in which the casting surface condition is excellent.

Abstract: Disclosed is a continuous casting method in which a melt obtained by melting titanium or a titanium alloy is poured into a bottomless mold and is drawn downward while being solidified, wherein: the surface of the melt in the mold is heated by horizontally moving a plasma torch over the surface of the melt; thermocouples are provided at a plurality of locations along the circumferential direction of the mold; if the temperature of the mold measured by one of the thermocouples is lower than a target temperature, then the output of the plasma torch is increased when the plasma torch comes close to the location where that thermocouple is installed; and if said temperature is higher than the target temperature, then the output of the plasma torch is decreased when the plasma torch comes close to the location where that thermocouple is installed.

Abstract: The continuous casting device according to the present invention enables at least some of a plurality of hearths (3) to be converted between being hearths (13) used for titanium, which are used during the continuous casting of titanium ingots, and being hearths (23) used for titanium alloy, which are used during the continuous casting of titanium alloy ingots. The number of hearths (23) used for titanium alloy is greater than the number of hearths (13) used for titanium. Also, the total capacity of the hearths (23) used for titanium alloy is greater than the total capacity of the hearths (13) used for titanium. Thus, titanium ingots and titanium alloy ingots can each be continuously cast by means of a single piece of equipment.

Abstract: A mold (2) has a cooling means (21) for having the thermal flux at four corner sections (2a) be smaller than the thermal flux at four face sections (2b). The cooling means (21) has first channels (22a) which are each embedded in the four corner sections (2a) respectively and which channel cooling water, and second channels (22b) which are each embedded in the four face sections (2b) respectively and which channel cooling water. The distance from the inner peripheral surface of the mold (2) to the first channels (22a) is greater than the distance from the inner peripheral surface of the mold (2) to the second channels (22b).

Abstract: By controlling the temperature (TS) of a surface portion (11a) of an ingot (11) in a contact region (16) between a mold (2) and the ingot (11) and/or a passing heat flux (q) from the surface portion (11a) of the ingot (11) to the mold (2) in the contact region (16), the thickness (D) in the contact region (16) of a solidified shell (13) obtained by the solidification of molten metal (12) is brought into a predetermined range. Consequently an ingot having a good casting surface state can be cast.

Abstract: The present invention is a method for manufacturing a titanium ingot (30), the method being characterized by comprising: a step of melting a titanium alloy for a predetermined time by cold crucible induction melting (CCIM); a step of supplying molten titanium (6) to a cold hearth (10), and separating high density inclusions (HDIs) (8) by precipitation in the cold hearth (10) while spraying a plasma jet or an electron beam onto the bath surface of the molten titanium (6); and a step of supplying a molten titanium starting material from which the HDIs (8) are separated by precipitation to a mold (20) to obtain the titanium ingot.

Abstract: A mold (2) has a cooling means (21) for having the thermal flux at four corner sections (2a) be smaller than the thermal flux at four face sections (2b). The cooling means (21) has first channels (22a) which are each embedded in the four corner sections (2a) respectively and which channel cooling water, and second channels (22b) which are each embedded in the four face sections (2b) respectively and which channel cooling water. The distance from the inner peripheral surface of the mold (2) to the first channels (22a) is greater than the distance from the inner peripheral surface of the mold (2) to the second channels (22b).