Apparatus and method for electron beam melting of recycled coarse-grained titanium alloy powder

Abstract

A kind of device and method for electron beam melting recycling coarse-grained section titanium alloy powder, device includes electron beam melting furnace, method is: titanium alloy bar pretreatment;Water-cooled copper crucible pretreatment, check furnace waterway;Titanium alloy bar is clamped in electron beam melting furnace, open water cooling machine, mechanical pump, Roots pump, diffusion pump and power switch, vacuumize electron gun and melting chamber, start 1# electron gun and hit titanium alloy bar, after melting, titanium alloy molten drop drops into water-cooled copper crucible;After melt spreads on bottom, start 2# electron gun, while open storage bin baffle, titanium alloy powder slides into water-cooled copper crucible, by controlling electron beam scanning path, make titanium alloy powder all melt;2# electron gun is used to refine titanium alloy powder in water-cooled copper crucible for 10 min, close power;After furnace body cooling, argon is passed into cooling, open furnace and take out titanium alloy ingot.The device of the application is reasonable, process is simple, recycling effect is good, while saving raw materials, improve production efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of titanium alloy powder recycling, and relates to a device and a method for recycling coarse-grained titanium alloy powder by electron beam melting. BACKGROUND

[0002] The laser selective melting technology is a new manufacturing technology based on the prototype manufacturing technology, and uses laser as a heat source to melt metal powder layer by layer to manufacture solid parts. With the super strong complex structure forming capacity, the super high material utilization rate and the rapid prototype manufacturing capacity, the laser selective melting technology provides a good solution for the manufacturing of complex structure titanium alloy parts in the fields of aviation, aerospace, weapons and ships, effectively saves raw materials, simplifies production processes, shortens design and manufacturing time, reduces manufacturing cost and risk.

[0003] Titanium alloy powder is the raw material for laser selective melting. Due to the limitation of the laser selective melting process, the particle size of the titanium alloy spherical powder mainly used is 15-53 mu m, and the powder above 53 mu m is less used at present, which is mainly used for steel smelting, fireworks additives, electron beam selective melting, etc. Its price is much lower than the production cost of raw materials and powder, and the amount is small, which cannot digest the coarse-grained powder produced by various factories. At present, the EIGA gas atomization powder manufacturing is the main manufacturing method of spherical titanium alloy powder for additive manufacturing. The titanium alloy powder above 53 mu m prepared by the method accounts for more than 50% of the total titanium alloy powder. A large amount of coarse-grained powder cannot be utilized, and is stacked in the warehouse, which is easy to cause safety hazards. In addition, due to the long stacking time of coarse-grained powder, the oxygen content is high, which cannot meet the requirements of titanium alloy raw materials on purity.

[0004] In view of the above problems, a method for recycling coarse-grained titanium alloy powder by electron beam melting is needed, which can effectively recycle and utilize coarse-grained powder and solve the problems of difficult recycling and high oxygen content of coarse-grained powder. SUMMARY

[0005] The first technical problem to be solved by the application is to provide a device for recycling coarse-grained titanium alloy powder by electron beam melting, which has the characteristics of reasonable structure and good recycling effect.

[0006] The second technical problem to be solved by the application is to provide a method for recycling coarse-grained titanium alloy powder by electron beam melting, which uses electron beam melting technology to melt and recycle coarse-grained titanium alloy powder, and has the characteristics of simple process and good recycling effect.

[0007] The technical scheme adopted by the present application to solve the first technical problem is: a device for recovering coarse-grained titanium alloy powder by electron beam melting, comprising an electron beam melting furnace, characterized in that: a storage bin for placing coarse-grained titanium alloy powder is concavely arranged in the middle of the upper end face of the electron beam melting furnace, a feeding pipe is connected to the lower end opening of the storage bin, a water-cooled copper crucible is arranged directly below the feeding pipe in the electron beam melting furnace, a clamping device for clamping a material rod is arranged on the inner side of the electron beam melting furnace, an electron gun is installed on the upper end of the electron beam melting furnace, and a Roots pump for vacuumizing and a pump device for vacuumizing the electron gun and an electron beam melting power switch are installed on the outer side of the electron beam melting furnace.

[0008] Further, the pump device comprises a diffusion pump, a pneumatic valve and a mechanical pump, the mechanical pump outputs through the pneumatic valve to connect the diffusion pump, and the diffusion pump is connected to the electron gun through a pipeline.

[0009] Further, a left-right slidable baffle plate is installed at the lower end opening position of the storage bin, and an observation window is arranged on one side of the upper part of the electron beam melting furnace.

[0010] Further, the material rod is a TC4 or TA15 titanium alloy rod, and two electron guns are installed on the upper end of the electron beam melting furnace and located on the left and right sides of the storage bin.

[0011] Finally, a furnace body cooling water pipe is installed on the inner wall of the electron beam melting furnace, the furnace body cooling water pipe is connected to a water cooling machine, a cooling water pipe inlet is arranged on the left side of the lower part of the furnace body, a cooling water pipe outlet is arranged on the right side of the furnace body, and a water-cooled copper crucible cooling water pipe is arranged at the bottom of the electron beam melting furnace.

[0012] The technical scheme adopted by the present application to solve the second technical problem is: a method for recovering coarse-grained titanium alloy powder by electron beam melting, characterized by: using the above device for recovery, and the specific steps are as follows:

[0013] 1) Preprocessing the titanium alloy rod;

[0014] 2) Preprocessing the water-cooled copper crucible in the electron beam melting furnace, and using a dust collector to suck the dust in the furnace, and checking whether the waterway of each part in the furnace leaks;

[0015] 3) Suspendedly clamping the titanium alloy rod preprocessed in step 1) in the feeding mechanism of the electron beam melting furnace, and closing the furnace door;

[0016] 4) Turning on the water cooling machine, the mechanical pump, the Roots pump, the diffusion pump and the electron beam melting power switch, and vacuumizing the electron gun and the melting chamber, when the vacuum degree of the melting chamber reaches 5x10 -2 Pa, and the vacuum degree of the electron gun chamber reaches 5x10 -3Pa below, start to start 1# electron gun titanium alloy rod to bombard, after melting titanium alloy droplets drop into water-cooled copper crucible;

[0017] 5) When the titanium alloy melt spreads on the bottom of the water-cooled copper crucible, start the 2# electron gun to melt the titanium alloy in the water-cooled copper crucible, and open the baffle of the upper storage bin at the same time, the titanium alloy powder slides into the titanium alloy melt in the water-cooled copper crucible, and the titanium alloy powder in the water-cooled copper crucible is completely melted by controlling the scanning path of the electron beam;

[0018] 6) The titanium alloy powder is slowly and continuously dropped into the water-cooled copper crucible by controlling the baffle of the storage bin until the titanium alloy powder in the storage bin is completely dropped, and the 2# electron gun is used to refine the titanium alloy powder in the water-cooled copper crucible for 10±2 min, and the power of the electron gun is turned off;

[0019] 7) After the furnace body is naturally cooled for 40±10 min, two times of argon gas are introduced to cool the furnace, and the furnace body is completely cooled to open the furnace and take out the titanium alloy ingot.

[0020] Further, the specific process of the pretreatment of step 1) is that the TC4 and TA15 titanium alloy rods are polished clean by using a grinding machine, then the polished TC4 and TA15 titanium alloy rods are cleaned by using deionized water and alcohol, and the titanium alloy surface is blown dry by using a hair dryer until completely dried.

[0021] Finally, the water-cooled copper crucible in step 2) is clean, which means that the water-cooled copper crucible is polished clean by using 200-1000# sandpaper, and the inner wall of the water-cooled copper crucible is wiped clean by using a dust-free cloth dipped with a small amount of alcohol.

[0022] Compared with the prior art, the application has the following advantages:

[0023] The electronic beam melting technology is adopted to recycle the coarse granularity section with large yield and low utilization rate, so that the preparation cost of the titanium alloy spherical powder can be reduced, and the titanium alloy coarse granularity section powder can be effectively melted through the steps of pre-preparing a molten pool and feeding powder; in addition, the internal oxygen content of the coarse granularity section titanium alloy powder is high due to long storage time, and the oxygen content can be further reduced through the electronic beam melting, so that the original oxygen content of the titanium alloy spherical powder can be reduced from about 1000 ppm to below 500 ppm, and the purity of the titanium alloy is effectively improved.

[0024] The electronic beam melting technology is adopted to recycle the coarse granularity section titanium alloy powder, and the application has the characteristics of reasonable device, simple process and good recycling effect, which not only effectively solves the problems of difficult recycling and high oxygen content of the coarse granularity section titanium alloy powder, but also saves raw materials and improves production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the device for electron beam melting and recycling coarse-grained titanium alloy powder provided by the present application. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below with reference to the embodiments of the drawings.

[0027] As shown in the drawings, Figure 1 A device for electron beam melting and recycling coarse-grained titanium alloy powder includes an electron beam melting furnace, a storage bin 4 for placing coarse-grained titanium alloy powder is recessed in the middle of the upper end face of the electron beam melting furnace, a feeding pipe 6 is connected to the lower end opening of the storage bin 4, a left-right slidable baffle 5 is installed at the lower end opening position of the storage bin 4, an observation window 13 is provided on one side of the upper part of the electron beam melting furnace; a water-cooled copper crucible 8 is provided in the electron beam melting furnace directly below the feeding pipe 5, a molten pool 9 is formed in the water-cooled copper crucible 8, a clamping device 14 for clamping a material rod 15 is provided on the inner side of the electron beam melting furnace, an electron gun 10 and 12 are installed on the upper end of the electron beam melting furnace, a Roots pump 7 for vacuumizing and a pump device for vacuumizing the electron gun and an electron beam melting power switch are installed on the outer side of the electron beam melting furnace, wherein the pump device is a mechanical pump 3 output connected to a diffusion pump 1 through a pneumatic valve 2, and the diffusion pump 1 is connected to the electron guns 10 and 12 through pipes respectively.

[0028] The material rod 15 is a TC4 or TA15 titanium alloy rod, and the electron guns 10 and 12 are two, which are installed on the upper end of the electron beam melting furnace and located on the left and right sides of the storage bin 4 respectively. A furnace body cooling water pipe 17 is installed on the inner wall of the electron beam melting furnace, the furnace body cooling water pipe 17 is connected to a water cooling machine, a cooling water pipe inlet is provided on the lower left side of the furnace body, a cooling water pipe outlet is provided on the right side, and a water-cooled copper crucible cooling water pipe 18 is provided on the bottom of the electron beam melting furnace.

[0029] A method for electron beam melting and recycling coarse-grained titanium alloy powder, which is recycled by using the above device, and the specific steps are as follows:

[0030] 1) Pre-treat the TC4 or TA15 titanium alloy rod 15: use a grinding machine to polish the surface of the TC4 or TA15 titanium alloy rod 15, then use deionized water and alcohol to clean the polished TC4 or TA15 titanium alloy rod 15, and use a hair dryer to dry the surface of the titanium alloy until it is completely dried;

[0031] 2) Pre-treat the water-cooled copper crucible 8 in the electron beam melting furnace and use a dust collector to suck out the dust in the furnace, and check whether the water in each part of the furnace leaks; the pre-treatment of the water-cooled copper crucible 8 means that the water-cooled copper crucible is polished clean using 200-1000# sandpaper, and the inner wall of the water-cooled copper crucible is wiped clean using a dust-free cloth dipped in a small amount of alcohol;

[0032] 3) The titanium alloy bar 15 after the pretreatment of step 1) is suspended and clamped in the feeding mechanism of the electron beam melting furnace, and the furnace door is closed;

[0033] 4) The water cooling machine, the mechanical pump 3, the Roots pump 7, the diffusion pump 1 and the electron beam melting power switch are turned on, the electron guns 10 and 12 and the melting chamber are vacuumized, and when the vacuum degree of the melting chamber reaches 5*10 -2 Pa, the vacuum degree of the electron gun chamber reaches 5*10 - 3 Pa, and then the 1# electron gun 12 is started to bombard the titanium alloy bar 15, and the melted titanium alloy droplets drop into the water-cooled copper crucible 8;

[0034] 5) When the titanium alloy melt spreads on the bottom of the water-cooled copper crucible 8, the 2# electron gun is started to melt the titanium alloy in the water-cooled copper crucible 8, and the baffle 5 of the upper storage bin 4 is opened, the titanium alloy powder 11 slides into the titanium alloy melt in the water-cooled copper crucible 8, and the titanium alloy powder is completely melted by controlling the scanning path of the electron beam; the high-energy-density electron beam is used to refine the titanium alloy melt, which can significantly reduce the oxygen content in the titanium alloy;

[0035] 6) The titanium alloy powder 11 is slowly and continuously dropped into the water-cooled copper crucible 8 by controlling the baffle 5 of the storage bin 4, until the titanium alloy powder 11 in the storage bin 4 is completely dropped, the 2# electron gun 10 is used to refine the titanium alloy powder in the water-cooled copper crucible 8 for 10 min, and the electron gun power is turned off;

[0036] 7) After the furnace body is naturally cooled for 40 min, argon is introduced twice to cool the furnace, and the titanium alloy ingot is taken out after the furnace is completely cooled.

[0037] Further, the pretreatment process of step 1) is that the TC4 and TA15 titanium alloy bars are polished clean by using a grinding machine, then the polished TC4 and TA15 titanium alloy bars are cleaned by using deionized water and alcohol, and the titanium alloy surface is blown dry by using a hair dryer until completely dried.

[0038] Finally, the water-cooled copper crucible in step 2) is polished clean by using 200-1000# sandpaper, and the inner wall of the water-cooled copper crucible is wiped clean by using a dust-free cloth dipped in a small amount of alcohol.

[0039] The present application adopts the electron beam melting technology to melt and recycle the coarse-grained titanium alloy powder into an ingot, and then the ingot is forged into a bar to become a gas atomization powder raw material, which effectively solves the problems of difficult recycling of coarse-grained titanium alloy powder and high oxygen content.

[0040] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the technical principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for recycling coarse-grained segment titanium alloy powder by electron beam melting, using an electron beam melting device; the electron beam melting device comprises an electron beam melting furnace, a storage bin for placing coarse-grained segment titanium alloy powder is recessed in the middle of the upper end face of the electron beam melting furnace, a feeding pipe is connected to the opening at the lower end of the storage bin, a water-cooled copper crucible is arranged directly below the feeding pipe in the electron beam melting furnace, a clamping device for clamping titanium alloy rods is arranged on the inner side of the electron beam melting furnace, an electron gun is installed on the upper end of the electron beam melting furnace, a Roots pump for vacuumizing and a pump device for vacuumizing the electron gun and a power switch of the electron beam melting are installed on the outer side of the electron beam melting furnace. The pump device comprises a diffusion pump, a pneumatic valve and a mechanical pump, the output of the mechanical pump is connected to the diffusion pump through the pneumatic valve, and the diffusion pump is connected to the electron gun through a pipeline. A left-right slidable baffle is installed at the opening position of the lower end of the storage bin, and an observation window is arranged on one side of the upper part of the electron beam melting furnace. The rod is a TC4 or TA15 titanium alloy rod, and two electron guns are installed on the upper end of the electron beam melting furnace, respectively on the left and right sides of the storage bin. A furnace body cooling water pipe is installed on the inner wall of the electron beam melting furnace, the furnace body cooling water pipe is connected to a water cooling machine, a cooling water pipe inlet is arranged on the left side of the lower part of the furnace body, and a cooling water pipe outlet is arranged on the right side, and a water-cooled copper crucible cooling water pipe is arranged at the bottom of the electron beam melting furnace. characterized in that The specific steps are as follows: 1) pretreat the titanium alloy rod; 2) pretreat the water-cooled copper crucible in the electron beam melting furnace, use a dust collector to suck out the dust in the furnace, and check whether the waterway of each part in the furnace leaks; 3) suspend and clamp the titanium alloy rod pretreated in step 1) in the feeding mechanism of the electron beam melting furnace, and close the furnace door; 4) Turn on the water cooling machine, mechanical pump, Roots pump, diffusion pump and electron beam melting power switch, and vacuumize the electron gun and melting chamber. When the vacuum degree of the melting chamber reaches 5 × 10 -2 Pa, start to start 1# electron gun to bombard titanium alloy bar, and the melted titanium alloy droplets drop into the water-cooled copper crucible. -3 Pa, start to start 1# electron gun to bombard titanium alloy bar, and the melted titanium alloy droplets drop into the water-cooled copper crucible. 5) when the titanium alloy melt covers the bottom of the water-cooled copper crucible, start the 2# electron gun to melt the titanium alloy in the water-cooled copper crucible, at the same time, open the baffle of the upper storage bin, the titanium alloy powder slides into the titanium alloy melt in the water-cooled copper crucible, and the titanium alloy powder in the crucible is completely melted by controlling the scanning path of the electron beam; 6) control the baffle of the storage bin to make the titanium alloy powder fall into the water-cooled copper crucible slowly and continuously until the titanium alloy powder in the storage bin is completely dropped, use the 2# electron gun to refine the titanium alloy powder in the water-cooled copper crucible for 10±2 min, and turn off the power of the electron gun; By electron beam melting, the original oxygen content of the titanium alloy spherical powder is reduced from 1000 ppm to below 500 ppm; 7) after the furnace body is naturally cooled for 40±10 min, introduce argon twice to cool the furnace, and after the furnace is completely cooled, take out the titanium alloy ingot.

2. The method of claim 1, wherein: The specific process of the pretreatment in step 1) is: use a grinding machine to polish the surface of the TC4 and TA15 titanium alloy rod clean, then use deionized water and alcohol to clean the polished TC4 and TA15 titanium alloy rod, use a hair dryer to dry the surface of the titanium alloy until completely dried.

3. The method of claim 1, wherein: The clean preprocessing of the water-cooled copper crucible in the step 2) refers to: using 200-1000# sandpaper to polish the water-cooled copper crucible, using a small amount of alcohol to wipe the inner wall of the water-cooled copper crucible.

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