TW201738389A - Unit cell titanium casting - Google Patents

Abstract

A system (5) and method (800) for unit cell casting of titanium or titanium-alloys is disclosed herein. The system (5) comprises an external chamber (45), a crucible (10) positioned within the external chamber (45), an induction coil (15) positioned around the crucible, an internal chamber (40) positioned within the external chamber (45), and a mold (30) positioned within the internal chamber (40). The external chamber (45) is evacuated and a pressurized gas is injected into the evacuated external chamber (45) to create a pressurized external chamber (45). An ingot (20) is melted within the crucible utilizing induction heating generated by the induction coil (15). The internal chamber (40) is evacuated to create an evacuated internal chamber (40). The titanium alloy material of the ingot (20) is completely transferred into the mold (30) from the crucible (10) using a pressure differential created between the external chamber (45) and the internal chamber (40).

Description

Titanium casting of unit lattice

The present invention relates to precision titanium casting. More specifically, the present invention relates to an apparatus and method for precision titanium casting using induction heating.

Various methods of titanium casting are well known. One such method involves a die casting process of a dewaxing procedure. Vacuum arc melting is another method in which a titanium ingot is melted by substantial heat generated by mutual discharge, thereby forming a molten liquid metal in the crucible and completing casting by titanium, the mutual discharge The process is carried out in a high current state by using a titanium ingot and a water-cooled copper crucible as a positive electrode and a negative electrode, respectively. Another method is vacuum induction melting in which an induction coil is wound on the outside of a split type water-cooled copper crucible. The electromagnetic force generated by the induction coil passes through a non-metallic isolation portion between the blocks of the copper crucible and then acts on a titanium ingot placed in the crucible. Then, a molten metal is formed in the crucible by the molten metal and the casting by titanium is completed. Vacuum induction melting and vacuum arc melting require the use of a water-cooled copper crucible that produces substantial heat loss. The actual power consumed is minimal (only 20% to 30% of the electricity actually acting on titanium). In addition, the preparation of the mold shell is extremely complicated and time consuming, which adds cost. In conventional casting techniques, the operating time of a single furnace typically ranges from 60 minutes to 80 minutes, and the loading and discharging processes require many people to collaborate. In the conventional casting technique, it takes ten days from the preparation of the wax model to the process of cleaning the mold casing. Titanium is an extremely reactive metal. A water cooling environment is required during melting through a conventional casting process. If the crucible breaks, the molten titanium liquid will come into direct contact with the water, causing a strong reaction or even an explosion, which poses a great threat to production safety. In order to solve the above problems, there is an urgent need for a new titanium alloy induction melting vacuum suction casting device to solve the problems associated with the existing titanium alloy casting method, such as low efficiency, high cost, complicated technology, heavy workload, and difficulty in preparing high quality molds. Housing, long cycle and potential hazard.

Currently, the loading of the preheated mold mold occurs between the preheating furnace and the foundry furnace. The model mold itself is currently attached to the underside of the top panel of the inner chamber using a forked wedge. The top plate, which is attached to the mold, is then inverted and placed onto the inner chamber body. In order to reduce the time required to load the model mold (thus minimizing heat loss) and to reduce the chance of damage to the model mold (caused by stress caused by damage during wedges and/or transport), a bracket should be used Support the mold. The stent will be formed in the inner chamber and specially designed to hold and orient the model. The model mold itself will be modified to form a funnel at the top of the main gate to allow material to flow into the mold and fill the mold. Using this feature will allow faster/more repeatable cycle times, which will minimize variations between parts. One aspect of the invention is a method for unit cell casting from titanium or a titanium alloy. The method includes evacuating an outer chamber to form an evacuated outer chamber, wherein a ceramic crucible containing one of the titanium alloy ingots is positioned in the outer chamber. The method also includes injecting a pressurized gas into the evacuated outer chamber to form a pressurized outer chamber. The method also includes melting the titanium alloy ingot in the ceramic crucible by induction heating generated by an induction coil positioned around the ceramic crucible. The method also includes evacuating the interior chamber to form an evacuated interior chamber, wherein a mold is positioned within the mold holder of the interior chamber. The method also includes transferring the fully melted titanium alloy material from the crucible into the mold using a pressure differential formed between the outer chamber and the inner chamber. One of the frequencies generated in the induction coil is in the range from 1 kHz to 50 kHz, and a power is in the range from 15 kW to 50 kW. The atmospheric pressure of one of the evacuated internal chambers ranges from 3 x 10 ^-2 atmospheres to 9.87 x 10 ^-7 atmospheres. The atmospheric pressure of one of the evacuated internal chambers ranges from 9.87 x 10 ^-7 atmospheres to 9.87 x 10 ^-13 atmospheres. The method further includes heating the mold using an infrared heating unit positioned within the interior chamber to form a heated mold. The method further includes cooling the titanium alloy within the mold. Another aspect of the invention is a system for unit lattice casting from titanium or a titanium alloy, the system comprising: an outer chamber; a ceramic crucible positioned in the outer chamber; an induction coil surrounding the The ceramic crucible is positioned in a bottom section; an interior chamber positioned in the outer chamber; a model mold holder positioned within the interior chamber; and a mold positioned within the model mold holder in the interior chamber. The outer chamber is evacuated to form an evacuated outer chamber, wherein the ceramic crucible contains a titanium alloy ingot positioned therein. A pressurized gas is injected into the evacuated outer chamber to form a pressurized outer chamber. The titanium alloy ingot is melted in the ceramic crucible by induction heating generated by the induction coil positioned around the ceramic crucible. The interior chamber is evacuated to form an evacuated interior chamber. The titanium alloy material is completely transferred from the crucible into the mold using a pressure difference formed between the outer chamber and the inner chamber. The pressurized gas is preferably argon. The mold is preferably covered with a kaolin insulation material. The mold is preferably used in a thin walled golf club head. The mold is instead used for an article having a wall thickness of less than 0.250 inches. The induction melting time is preferably in the range of from 30 seconds to 90 seconds. The ceramic crucible preferably consists of two main ruthenium layers based on ruthenium oxide, wherein a first major ruthenium layer has a thickness ranging from 0.010 ft to 0.060 ft, and a second major ruthenium layer It has a thickness ranging from 0.001 inches to 0.020 inches. The ceramic crucible further includes a reinforcing layer based on cerium oxide. The induction coil is preferably positioned around a bottom section of the ceramic crucible. The induction coil is instead positioned around an upper section of the ceramic crucible. The above and other objects, features and advantages of the present invention will become apparent from the <RTIgt;

As shown in FIG. 1, a unit cell titanium casting system 5 includes an outer container 44, an inner container 39, a vacuum mechanism 60, a crucible 10, an induction coil 15, a coil electric generating mechanism 25, and a mold. 30. The outer container 44 defines an outer chamber 45. The inner container 39 defines an interior chamber 40. The vacuum mechanism 60 includes a vacuum line 71, a vacuum connector 70, and pressure gauges 75a and 75b. The vacuum mechanism 60 is for evacuating and pressurizing the outer chamber 45 and the inner chamber 40 to form a pressure difference between the inner chamber 40 and the outer chamber 45. The crucible 10 is preferably constructed of a ceramic material. In a preferred embodiment, the crucible 10 is comprised of a first layer 11a, a second layer 11b, and a third layer 11c based on ceria, as shown in FIG. A metal ingot 20 is placed inside the crucible 10. The metal ingot 20 is preferably a titanium alloy material. The volume of the crucible 10 preferably corresponds to the amount of metal required to form the article. The interior of the crucible 10 preferably has a diameter ranging from 15 cm ("cm") to 90 cm, more preferably from 35 cm to 60 cm. One of the heights of the crucible 10 is preferably in the range of from 30 cm to 200 cm and more preferably in the range of from 60 cm to 100 cm. A connecting nozzle 27 is coupled between one of the bottom openings (not shown) of the crucible 10 and one of the openings of the mold 30. The connecting nozzles 27 allow molten metal material to flow from the ingot 20 into the mold 30 for casting the article. In particular, the size of the attachment nozzle 27 is determined based on the size and shape of the cavity of the mold 30, and preferably ranges from 5 cm to 100 cm, and more preferably from 15 cm to 50 cm. Within the scope. The induction coil 15 is wound around the crucible 10. The induction coil 15 is energized to generate an electromagnetic force to melt the metal ingot 20 (e.g., titanium alloy ingot) in the crucible 10. The coil electric generating mechanism 25 supplies electric power to the induction coil 15. As shown in FIG. 2, the induction coil 15 is wound around one of the bottom sections 10b of the crucible 10. This first melts the bottom of the ingot 20. As shown in FIG. 2A, the induction coil 15 is wound around one of the upper sections 10a of the crucible 10. This first melts the top of the ingot 20. In order to optimize the ability of the target material to seal around the port of a ceramic crucible 10, the induction coil 15 is preferably centered about one third of the upper portion of the ingot 20. This positioning allows the induction coil 15 to first act on the upper portion of the ingot 20 (melting the material from top to bottom), causing the molten material to fall around the still solid ingot 20 and the electromagnetic force on the induction coil 15 affecting the rest. A seal is formed before the material. Alternatively, to fully utilize the electromagnetic force of the induction coil 15 (including electromagnetic stirring of the melt), the induction coil 15 is positioned toward the bottom 10b of the ceramic crucible 10. This positioning allows a uniform melt to fall on itself as a molten material and increase the homogeneity of the pour, since the electromagnetic force preferably acts on the molten material before the molten material is evacuated from the crucible 10. The melting of the titanium alloy ingot 20 is carried out under vacuum conditions for induction melting. The induction coil 15 is connected to the coil electric generating mechanism 25. The ceramic crucible 10 is used for vacuum induction melting of titanium alloy. The ceramic material does not interfere with the field effect of the electromagnetic force, and the electromagnetic induction energy generated by the induction coil 15 is sufficiently concentrated to melt the titanium alloy ingot. In one embodiment shown in Figure 2B, an insulating material 31 is wrapped around the mold 30. During casting, the mold is preheated prior to use to improve the flow of material into the mold itself and to better allow the mold to be molded. 30 is completely filled. Due to the nature of the titanium material and the melting process itself, the resulting heat loss is minimized, and the longer the material must flow and fill the mold 30 prior to solidification. To this end, the mold mold heat is preserved by using an insulating material 31 (e.g., kaolin), thereby extending the life cycle of the mold 30 prior to pouring and allowing for better filling, including castings that are more difficult to fill (e.g., Thin-walled castings). As shown in Figures 3A, 3B, 3C, 3D and 3E, the mold 30 is preheated in a furnace 80. During unit cell casting, the mold mold 30 is preheated prior to use to improve the flow of the modified material into the mold 30 itself and better allow the mold 30 to be completely filled. Due to the nature of the titanium material and the melting process itself, there is a possible correlation between the temperature of the mold 30 and the ability to fill the complex and/or thin-walled model mold 30. The temperature test includes 1050 ° C, 1060 ° C, 1100 ° C, 1150 ° C, 1200 ° C, 1250 ° C and 1260 ° C. The preheated mold is removed from 80 and attached to one of the lids 35 of the inner container 39. In an alternate embodiment shown in FIG. 3F, infrared heaters 50a and 50b are used within internal chamber 40 to maintain the heat of mold 30. Due to the nature of the titanium material and the melting process itself, the resulting heat loss is minimized, and the longer the material can flow and fill the mold 30 prior to solidification. To this end, the mold mold heat is preserved by using the infrared heaters 50a and 50b placed in the inner wall of the inner chamber 40 of the inner container 39 to minimize the cooling of the mold and improve the casting complexity and/or thin wall. The ability of the part. 4, 4A, and 4B illustrate a casting process that uses a pressure differential between the outer chamber 45 and the inner chamber 40 to help flow the molten titanium alloy material into a mold 30. FIG. 5 illustrates the use of a programmable logic computer ("PLC") and an operator computer 91 in conjunction with a unit cell casting system 5. Figure 6 is a block diagram of a unit cell casting method 600. At step 601, an ingot 20 is prepared for casting. A single ingot 20 is used to make a single item, such as a golf club head 29. Unlike the manufacture of multiple articles in a single process (which results in material loss), the present invention produces only a single article in each process. At step 602, the mold 30 is preheated in a furnace. At step 603, the outer chamber 45 is evacuated. At step 604, the outer chamber 45 is pressurized with an argon gas. At step 605, the interior chamber 40 is evacuated. At step 606, the induction coil 15 is energized, and at step 607, the ingot 20 is melted within the crucible 10. At step 608, the molten material flows into the mold 30. At step 609, a demolding process occurs. At step 610, the item (golf club head) 29 is completed. One of the frequencies generated in the induction coil is in the range from 1 kHz to 50 kHz, and a power is in the range from 15 kW to 50 kW. The atmospheric pressure of one of the evacuated internal chambers ranges from 3 x 10 ^-2 atmospheres to 9.87 x 10 ^-7 atmospheres. The atmospheric pressure of one of the evacuated internal chambers ranges from 9.87 x 10 ^-7 atmospheres to 9.87 x 10 ^-13 atmospheres. As shown in Figure 7, the first layer 11a and the second layer 11b are preferably constructed of yttria and other materials. Cerium oxide is highly inert to titanium in a high temperature environment and thus does not chemically react between the two materials. Cerium oxide also isolates the ceramic material from the titanium during the melting process to prevent reaction between the ceramic material and the titanium to ensure smooth melting of the titanium alloy. The third layer 11c of the crucible 10 is preferably composed of ceria and other materials. Cerium oxide resists metal expansion and thermal stress during the melting process to ensure the strength of the crucible. One of the first layers 11a preferably has a thickness of from 0.5 mm to 1.5 mm and a preferred thickness of the crucible 10 ranges from 5 mm to 15 mm. One method 800 for unit cell casting from titanium or a titanium alloy is shown in FIG. At block 801, an outer chamber is evacuated to form an evacuated outer chamber in which a ceramic crucible containing one of the titanium alloy ingots is positioned. At block 802, a pressurized gas is injected into the evacuated outer chamber to form a pressurized outer chamber. At block 803, the titanium alloy ingot in the ceramic crucible is melted using induction heating generated by an induction coil positioned around the ceramic crucible. At block 804, the interior chamber is evacuated to form an evacuated interior chamber, with a mold positioned within the interior chamber. At block 805, a fully melted titanium alloy material is transferred from the crucible to the mold using a pressure differential formed between the outer chamber and the inner chamber.

5‧‧‧Unit Titanium Casting System / Unit Lattice Casting System / System
10‧‧‧坩埚/ceramics
10a‧‧‧ upper section
10b‧‧‧Bottom section/bottom
11a‧‧‧ first floor
11b‧‧‧ second floor
11c‧‧‧3rd/third layer based on cerium oxide
15‧‧‧Induction coil
20‧‧‧Metal ingots/ingots/still solid ingots
25‧‧‧ coil electric generating mechanism
27‧‧‧Connecting nozzle
29‧‧‧Golf club head/items
30‧‧‧Mold/Model Mold/Complex and/or Thin Wall Model Mold
31‧‧‧Insulation materials
35‧‧‧ Cover
39‧‧‧Internal containers
40‧‧‧Internal room/evacuated interior room
44‧‧‧External containers
45‧‧‧External room/extracted external room/pressurized external room
50a‧‧‧Infrared heater
50b‧‧‧Infrared heater
60‧‧‧vacuum mechanism
70‧‧‧vacuum connector
71‧‧‧vacuum pipeline
75a‧‧‧ pressure gauge
75b‧‧‧ pressure gauge
80‧‧‧ furnace
91‧‧‧Operator computer

Figure 1 is an illustration of one unit of a lattice casting system. 2 is a separate view of one of the interior chambers, turns, induction coils, and molds of a unitary lattice casting system showing the induction coils placed at a lower section of the crucible. 2A is a separate view of one of the interior chambers, turns, induction coils, and molds of a unitary lattice casting system showing the induction coil placed at an upper section of the crucible. 2B is a separate view of one of the interior chambers, crucibles, induction coils, and molds of one of the unit cell casting systems, showing an insulating material wrapped around the mold. Figure 3A is a diagram of one of the technicians preheating a mold in a furnace. Figure 3B is an illustration of one of the technicians attaching a preheated mold to one of the inner containers. Figure 3C is an illustration of one of the technicians attaching a lid to an inner container. Figure 3D is a separate view of one of the internal containers. Figure 3E is a separate view of one of the covers of the inner container. Figure 3F is a separate view of one of the interior compartments of the inner container showing an infrared heater. Figure 4 is an illustration of one of the unit cell casting systems during an external chamber evacuation step. Figure 4A is an illustration of one of the unit cell casting systems during an external chamber pressurization step. Figure 4B is an illustration of one of the unitary lattice casting systems during an ingot melting step. Figure 5 is an illustration of one of the PLC units and computers used in a unit cell casting system. Figure 6 is a block diagram of a unit cell casting method. Figure 7 is a separate view of one of the unitary lattice casting systems. Figure 8 is a flow chart of one of the methods for titanium casting in a unit cell.

5‧‧‧Unit Titanium Casting System / Unit Lattice Casting System / System

10‧‧‧坩埚/ceramics

15‧‧‧Induction coil

20‧‧‧Metal ingots/ingots/still solid ingots

25‧‧‧ coil electric generating mechanism

30‧‧‧Mold/Model Mold/Complex and/or Thin Wall Model Mold

39‧‧‧Internal containers

40‧‧‧Internal room/evacuated interior room

44‧‧‧External containers

45‧‧‧External room/extracted external room/pressurized external room

60‧‧‧vacuum mechanism

70‧‧‧vacuum connector

71‧‧‧vacuum pipeline

75a‧‧‧ pressure gauge

75b‧‧‧ pressure gauge

Claims (20)

A method for unit cell casting from titanium or a titanium alloy, the method comprising: evacuating an outer chamber to form an evacuated outer chamber, wherein one of the titanium alloy ingots is positioned in the outer chamber; a pressurized gas is injected into the evacuated outer chamber to form a pressurized outer chamber; the titanium alloy ingot in the crucible is melted by induction heating generated by an induction coil positioned around the crucible; the internal chamber is evacuated Forming an evacuated inner chamber, wherein a mold is positioned in the inner chamber; and transferring the fully melted titanium alloy material from the crucible into the mold using a pressure difference formed between the outer chamber and the inner chamber; Wherein a frequency generated in the induction coil is in a range from 1 kHz to 50 kHz, and a power is in a range from 15 kW to 50 kW; wherein the atmospheric pressure of the evacuated internal chamber is in the range from atmospheric to 9.87 × 10 ^-7 atm of 3 × 10 ^-2; wherein one of the atmospheric pressure by evacuating the interior of the chamber between the atmospheric pressure from 9.87 × 10 ^-7 to 9.87 × 10 ^-13 atm and Fan Inside. The method of claim 1, wherein the pressurized gas system is argon. The method of claim 1, wherein the mold is covered with a kaolin insulation material. The method of claim 1, further comprising heating the mold using an infrared heating unit positioned within the interior chamber to form a heated mold. The method of claim 1, wherein the mold is for a thin-walled golf club head. The method of claim 1, wherein the mold is for an article having a wall thickness of less than 0.250 inches. The method of claim 1, wherein the induction melting time is in the range of from 30 seconds to 90 seconds. The method of claim 1, wherein the crucible is composed of two main crucible layers based on cerium oxide, wherein a first major crucible layer has a thickness ranging from 0.010 inches to 0.060 inches, and a The two major layers have a thickness ranging from 0.001 inches to 0.020 inches. The method of claim 7, further comprising a reinforcing layer based on cerium oxide. The method of claim 1, further comprising cooling the titanium alloy within the mold. The method of claim 1, wherein the inductive coil is positioned around a bottom section of the crucible. The method of claim 1, wherein the induction coil is positioned around an upper section of the crucible. A system for unit lattice casting from titanium or a titanium alloy, the system comprising: an outer chamber; a ceramic crucible positioned in the outer chamber; an induction coil positioned around the ceramic crucible; an interior chamber Positioning in the outer chamber; a model mold holder located in the inner chamber; and a mold positioned in the model mold holder in the inner chamber; wherein the outer chamber is evacuated to form an evacuated outer chamber, wherein The ceramic crucible contains a titanium alloy ingot positioned therein; wherein a pressurized gas is injected into the evacuated outer chamber to form a pressurized outer chamber; wherein the titanium alloy ingot is positioned by surrounding the ceramic crucible The induction coil generates induction heating to be melted in the ceramic crucible; wherein the inner chamber is evacuated to form an evacuated inner chamber; wherein the titanium alloy material uses a pressure difference formed between the outer chamber and the inner chamber The crucible is completely transferred from the crucible. The system of claim 13 further comprising an infrared heating unit in the interior chamber, wherein the mold is heated using an infrared heating unit positioned in the interior chamber to form a heated mold. A system of claim 13 wherein the mold is for a thin walled golf club head. The system of claim 13 wherein the mold is for an article having a wall thickness of less than 0.250 inches. The system of claim 13, wherein the ceramic crucible is composed of two main tantalum layers based on ruthenium oxide, wherein a first major tantalum layer has a thickness ranging from 0.010 inches to 0.060 inches, and one The second major layer has a thickness ranging from 0.001 inches to 0.020 inches. The system of claim 13 wherein the inductive coil is positioned around a bottom section of the ceramic crucible. The system of claim 13, wherein the induction coil is positioned around an upper section of the ceramic crucible. The system of claim 13 wherein the mold is covered with a kaolin insulation material.