CN115026285A

CN115026285A - Titanium-based workpiece and hot isostatic pressing preparation method thereof

Info

Publication number: CN115026285A
Application number: CN202210443017.9A
Authority: CN
Inventors: 路新
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2022-04-26
Filing date: 2022-04-26
Publication date: 2022-09-09

Abstract

A titanium substrate and a hot isostatic pressing preparation method thereof, wherein the titanium substrate is prepared by hot isostatic pressing, and the method comprises the following steps: pretreating a metal sheath for hot isostatic pressing; sealing and welding the upper end cover, the lower end cover and the exhaust pipe of the metal sheath with the cylinder body by adopting an argon arc welding machine, checking whether a welding seam has defects or not, and checking air tightness; a vibrating method is adopted to fill the metal sheath with good air tightness with the near-spherical titanium alloy powder obtained after screening and drying, and the metal sheath is fully vibrated to ensure the filling of the metal sheath; vacuumizing the metal sheath by adopting a sheath thermal degassing system, and sealing and welding a vacuumizing tube of the metal sheath by using a hydraulic clamp matched with argon arc welding; putting the vacuumized and seal-welded metal sheath into a hot isostatic pressing furnace, raising the temperature and the pressure to set temperature and pressure, and preserving the heat and the pressure for set time; and releasing the pressure, cooling the workpiece in a furnace to below 200 ℃, and taking out the workpiece from the metal sheath to obtain a titanium-based workpiece finished product. The invention has simple process, short period, high material utilization rate and high precision of the finished piece.

Description

Titanium-based workpiece and hot isostatic pressing preparation method thereof

Technical Field

The invention relates to a metal material and a preparation technology thereof, in particular to a high-performance titanium-based product based on low-cost titanium-based powder and a hot isostatic pressing preparation method thereof.

Background

In the prior art, part of the shell serving as a main bearing part presents a deep-cavity thin-wall complex structure, and is subjected to the test of complex bearing such as cyclic variable load and the like under severe conditions such as high load, high speed and the like in actual work, so that the high requirement on the reliability of a finished piece is provided, and great difficulty and challenge are brought to the forming of a corresponding component. In the prior art, a titanium alloy shell is mostly manufactured by adopting an investment casting or section plate/forging splicing or rivet welding connection method, but investment casting alloy workpieces have thick tissues and difficult control of metallurgical defects, so that the performance of the workpieces is low, and in addition, for non-machined surfaces, the control limit of 0.3mm of dimensional accuracy is difficult to break through; the multi-section rolling plate/forging blank processing and tailor welding/riveting forming method has the problems of insufficient integral rigidity, lower dimensional precision, poor surface smoothness, difficult quality control of welding seam parts and the like, and is increasingly difficult to meet the application requirements.

The NNS-HIP (Near-net-shape hot-isostatic-pressing) technology has the advantages of relatively simple process, short process period and high material utilization rate, can realize the integral manufacture of thin-wall complex titanium components, and the formed parts have uniform and fine tissues, and the performance of the formed parts can reach or even exceed the level of forged pieces. The high-quality spherical powder raw material is the basis of the titanium powder hot isostatic pressing technology and is the key for determining the cost and the performance of the finished product. Currently, spherical powder prepared by an inert GAs atomization method (GA) and a plasma rotating electrode method (PREP) can ensure reliable operation of the process and the quality of a finished piece due to good fluidity and high purity, and becomes a key raw material of NNS-HIP technology. However, the price of atomized spherical titanium powder is extremely expensive, and although the industry has been dedicated to developing low-cost and large-scale production processes of spherical titanium powder for decades, the cost control of the preparation technology of spherical powder including gas atomization is close to the limit, and the preparation technology is difficult to meet the requirement of rapid development of the current hot isostatic pressing technology, so that the atomized spherical titanium powder becomes a bottleneck which restricts the technical progress and wide application in the field. Therefore, it is an urgent technical problem in the art to develop a low-cost and high-performance titanium powder suitable for the hot isostatic pressing technique and to reduce the cost of the powder material for hot isostatic pressing.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a titanium base part and a hot isostatic pressing preparation method thereof aiming at the defects in the prior art.

In order to achieve the above object, the present invention provides a hot isostatic pressing method for preparing a titanium substrate, comprising the steps of:

s100, sleeving a metal sheath for hot isostatic pressing in alcohol, ultrasonically cleaning, removing dust and oil stains on the surface, and drying the cleaned metal sheath;

s200, sealing and welding an upper end cover, a lower end cover and an exhaust pipe of the metal sheath with the cylinder by adopting an argon arc welding machine, checking whether defects exist at a welding seam, and performing air tightness check by using a helium leak detector;

s300, filling the metal sheath with good air tightness by adopting a vibration method with the near-spherical titanium alloy powder obtained after screening and drying, and fully vibrating to ensure that the metal sheath is filled;

s400, performing vacuum pumping treatment on the metal sheath by adopting a sheath thermal degassing system, and performing seal welding on a vacuum pumping pipe of the metal sheath by using a hydraulic clamp matched with argon arc welding;

s500, placing the metal sheath which is vacuumized and sealed and welded into a hot isostatic pressing furnace, raising the temperature and the pressure to set temperature and set pressure, and keeping the temperature and the pressure for set time; and

s600, releasing the pressure, cooling the furnace to below 200 ℃, and taking out the part from the metal sheath to obtain a titanium-based part finished product.

The hot isostatic pressing preparation method of the titanium substrate further comprises the following steps:

s700, testing the compactness, tensile strength and elongation of the titanium base part.

In the hot isostatic pressing preparation method of the titanium substrate, in step S200, the gas tightness of the metal sheath meets the requirement that the leakage rate is less than 1.0 × 10 in a vacuum mode ^-9 Pa.m ³ /s。

In the above method for preparing a titanium substrate by hot isostatic pressing, in step S400, the metal capsule is vacuumized by using a capsule thermal degassing system, and the method further includes:

s401, vacuumizing the metal sheath to the vacuum degree of 1.0 x 10 at room temperature ^-3 Pa or less; and

s402, placing the metal sheath into a well type heating furnace to be heated to 550 ℃, and enabling the vacuum degree to reach 1.0 multiplied by 10 ^-3 After Pa or less, the reaction was kept for 5 hours.

In the hot isostatic pressing preparation method of the titanium substrate, in step S500, the set temperature is 800-1000 ℃, the set pressure is 80-130MPa, and the set time is 3-5 h.

In the hot isostatic pressing preparation method of the titanium substrate, the near-spherical titanium-based powder in the step S300 is prepared by the following steps:

s301, cleaning and drying the titanium waste, removing surface impurities, and carrying out hydrogenation reduction impurity removal in a rotary furnace; then cleaning, crushing and dehydrogenating the hydrogen absorption material, and secondarily crushing and screening the dehydrogenated material to obtain irregular hydrogenated and dehydrogenated titanium powder with specified granularity;

s302, placing the irregular hydrogenated and dehydrogenated titanium powder and zirconia balls into a high-temperature ball-milling tank according to a set ball-to-material ratio, placing the high-temperature ball-milling tank into a rotary furnace tube, introducing a set amount of argon, exhausting air in the rotary furnace tube and the high-temperature ball-milling tank, and enabling the irregular hydrogenated and dehydrogenated titanium powder to be in an inert gas protection environment;

s303, after the air in the furnace tube of the rotary furnace and the air in the high-temperature ball-milling tank are completely exhausted, opening a heating system of the rotary furnace, heating to a set temperature at a set heating rate, opening the rotary system of the rotary furnace, carrying out ball milling at a set rotating speed at a constant temperature, and continuously and stably introducing argon in the whole process at the set speed;

s304, after the high-temperature ball milling is finished, closing a heating system and a rotating system of the rotating furnace to cool the powder along with the furnace and continuously and stably introducing argon; after cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank, and separating titanium powder from zirconia balls;

s305, classifying and screening the powder collected after high-temperature ball milling, wherein the difference of the sizes of the sieve pores of adjacent sieves is less than or equal to 15 mu m, and only taking the powder between the adjacent sieves;

s306, drying the screened powder at 60 ℃ for 2-3h by using a vacuum drying oven, and carrying out vacuum packaging and storage on the dried powder for preparing the titanium substrate by hot isostatic pressing.

In the hot isostatic pressing preparation method of the titanium substrate, in the step S301, the cleaning reagent is a degreasing agent and a mixed solution of 10% HCl and 10% HF, the reducing agent for hydrogenation reduction is calcium and magnesium hydride, the reduction temperature is 600-; cleaning the hydrogen absorption material by using distilled water and a 10% HCl solution in sequence; the dehydrogenation temperature is 600-700 ℃, the time is 5-30h, and the grain diameter of the powder obtained after secondary crushing and screening is 50-120 mu m.

In the hot isostatic pressing preparation method of the titanium substrate, in step 302, the mass of the irregular hydrogenated dehydrogenated titanium powder is 50-1000 g; the mass ratio of the zirconia balls to the hydrogenated and dehydrogenated titanium powder is 0.5-2: 1; the diameters of the zirconia balls are respectively 6mm and 3mm, and the ratio of the zirconia balls with the diameters of the two is 1: 1; the flow rate of the argon is 1-1.5L/min, and the aeration time is 30-60 min.

In the hot isostatic pressing preparation method of the titanium substrate, in the step S303, the temperature rise rate of the rotary furnace is 5-10 ℃/min, and the temperature rises to 600 ℃; the rotating speed of the rotary furnace is 30-60rpm, and the rotating time is 5-10 h; the flow rate of the argon is 1-1.5L/min.

In order to better achieve the above object, the present invention also provides a titanium substrate prepared by the hot isostatic pressing preparation method of the titanium substrate.

The invention has the technical effects that:

the invention utilizes waste residual titanium to prepare a low-cost high-performance titanium base part through a hot isostatic pressing technology, firstly prepares titanium waste into irregular hydrogenated dehydrogenated titanium powder through a hydrogenated dehydrogenation method, then adopts a high-temperature ball milling technology, shapes the irregular titanium powder into nearly spherical titanium powder based on a thermoplastic deformation principle, realizes the low cost of the titanium powder for powder hot isostatic pressing, and finally prepares the low-cost high-performance titanium alloy part through the hot isostatic pressing technology, can meet the light and high-performance requirements of the development of the modern aerospace technology on high-temperature structural materials, and has higher value on the healthy development of the titanium powder market and the low cost of related titanium products.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

FIG. 1 is a diagram of an article made according to one embodiment of the present invention;

FIG. 2 is a schematic diagram of a titanium powder preparation method according to an embodiment of the present invention;

FIG. 3 is a schematic view of a high temperature ball milling jar in accordance with one embodiment of the present invention;

FIG. 4 is a scanning electron micrograph of the titanium powder prepared in example 1 of the present invention before reshaping;

FIG. 5 is a scanning electron micrograph of the titanium powder prepared in example 1 of the present invention after reshaping.

Wherein the reference numerals

1 rotating furnace tube

2 high-temperature ball milling tank

3 can lid

4 vent hole

5 tank body

6 card slot

7 materials to be processed

Detailed Description

The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:

referring to fig. 1, fig. 1 is a diagram of an article made according to one embodiment of the present invention. Aiming at the requirements of development of aerospace technology on light-weight, high-strength and high-temperature-resistant titanium alloy materials, titanium waste materials are prepared into irregular titanium powder by utilizing the reversible characteristic of hydrogen in titanium through a hydrogenation dehydrogenation method, on the basis, the irregular Hydrogenation Dehydrogenation (HDH) titanium powder is shaped into near-spherical titanium powder by utilizing a high-temperature ball milling technology based on a thermoplastic deformation principle, and a complex thin-wall titanium alloy part is prepared by adopting an NNS-HIP (nickel-zinc sulfide) technology, so that the requirements of modern development of aerospace technology on light weight and high performance of high-temperature structural materials can be met. The titanium base part is prepared by a hot isostatic pressing method, and comprises the following steps:

s100, pretreating a metal sheath for hot isostatic pressing, ultrasonically cleaning the metal sheath in alcohol to remove dust and oil stains on the surface, and drying the cleaned metal sheath;

step S200, adopting an argon arc welding machineSealing and welding an upper end cover, a lower end cover and an exhaust pipe of the metal sheath with the cylinder body, checking whether defects exist at a welding seam, and performing air tightness check by using a helium leak detector, wherein the air tightness of the metal sheath meets the condition that the leakage rate is less than 1.0 multiplied by 10 under a vacuum mode ^-9 Pa.m ³ /s；

S300, adopting a vibration method to fill the metal sheath with good air tightness with the near-spherical titanium alloy powder obtained after screening and drying, and fully vibrating to ensure that the metal sheath is filled;

step S400, a metal sheath is vacuumized by adopting a sheath thermal degassing system, and a vacuumizing tube of the metal sheath is sealed and welded by using a hydraulic clamp and argon arc welding;

s500, placing the metal sheath which is vacuumized and sealed and welded into a hot isostatic pressing furnace, raising the temperature and the pressure to set temperature and set pressure, and keeping the temperature and the pressure for set time, wherein the set temperature is preferably 800-1000 ℃, the set pressure is preferably 80-130MPa, and the set time is preferably 3-5 h; and

and S600, releasing the pressure, cooling the workpiece in a furnace to below 200 ℃, and taking out the workpiece from the metal sheath to obtain a finished product of the titanium-based workpiece.

In this embodiment, the method further includes the following steps:

step S700, testing the compactness, tensile strength and elongation of the titanium base part.

In step S400, a jacket thermal degassing system is used to perform vacuum pumping on the metal jacket, and the method further includes:

step S401, vacuumizing the metal sheath to the vacuum degree of 1.0 multiplied by 10 at room temperature ^-3 Pa below; and

s402, putting the metal sheath into a well type heating furnace to be heated to 550 ℃ and enabling the vacuum degree to reach 1.0 multiplied by 10 ^- ³ After Pa is below, the reaction is kept for 5 h.

Referring to fig. 2 and 3, fig. 2 is a schematic diagram illustrating a titanium powder preparation method according to an embodiment of the present invention, and fig. 3 is a schematic diagram illustrating a high temperature ball milling tank 2 according to an embodiment of the present invention. In this embodiment, the raw material of the near-spherical titanium-based powder in step S300 is prepared by the following equipment and process: the method comprises the steps of communicating a rotary furnace with an inert gas source, arranging vent holes 4 on a tank cover 3 of a high-temperature ball milling tank 2, arranging a clamping groove 6 connected with the inner wall of a rotary furnace tube 1 on a tank body 5 of the high-temperature ball milling tank 2, fixedly connecting the tank cover 3 with the tank body 5 through fixing screws after a material 7 to be processed is placed into the tank body 5, connecting the tank body 5 with the rotary furnace tube 1 through the clamping groove 6 and a top thread, and arranging a heating system and a rotating system on the rotary furnace, wherein the rotary furnace drives the high-temperature ball milling tank 2 to rotate, so that the material 7 to be processed positioned in the tank body 5 and the inner wall of the tank body 5 perform relative motion, and the material 7 to be processed and the tank body 5 are subjected to mutual friction and collision, so that the surface morphology and the particle size distribution of the material 7 to be processed are improved. The preparation of the near-spherical titanium-based powder is completed by the following steps:

step S302, placing the irregular hydrogenated and dehydrogenated titanium powder and zirconia balls into a high-temperature ball-milling tank according to a set ball-to-material ratio, placing the high-temperature ball-milling tank into a rotary furnace tube, introducing a set amount of argon, exhausting air in the rotary furnace tube and the high-temperature ball-milling tank, and enabling the irregular hydrogenated and dehydrogenated titanium powder to be in an inert gas protection environment;

step S303, after the air in the furnace tube of the rotary furnace and the high-temperature ball milling tank is completely exhausted, opening a heating system of the rotary furnace, heating to a set temperature at a set heating rate, opening the rotary system of the rotary furnace, carrying out ball milling at a set rotating speed at a constant temperature, and continuously and stably introducing argon gas at the set speed in the whole process;

step S304, after the high-temperature ball milling is finished, closing a heating system and a rotating system of the rotating furnace to cool the powder along with the furnace and continuously and stably introducing argon; cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank, and separating titanium powder from zirconia balls;

and S306, drying the screened powder at 60 ℃ for 2-3h by using a vacuum drying oven, and carrying out vacuum packaging and storage on the dried powder. Steps S301-S306 may be repeated multiple times according to the amount of powder required for printing, and the powders prepared multiple times may be mixed uniformly, dried and vacuum packaged for storage for use in hot isostatic pressing for preparing titanium articles. The method comprises the steps of carrying out high-temperature ball milling on hydrogenated and dehydrogenated titanium powder, wherein a small amount of the hydrogenated and dehydrogenated titanium powder can be taken for testing before vacuum packaging, detecting the shape, the flowability and the oxygen content of the hydrogenated and dehydrogenated titanium powder after high-temperature ball milling through a scanning electron microscope, a Hall flow meter and an inert gas pulse infrared thermal conductivity method, and calculating the difference between the oxygen content of treated powder and the oxygen content of untreated powder to obtain the powder oxygen increment of the hydrogenated and dehydrogenated titanium powder.

After step S301 in this embodiment, the oxygen content of the irregular hydrogenated and dehydrogenated titanium powder can be measured by using an inert gas pulse infrared thermal conduction method. In step S301, the cleaning reagent is a degreasing agent and a mixed solution of 10% HCl and 10% HF, the reducing agent for hydrogenation reduction is calcium and magnesium hydride, the reduction temperature is 600-; cleaning the hydrogen absorption material by using distilled water and a 10% HCl solution in sequence; the dehydrogenation temperature is 600-700 ℃, the time is 5-30h, and the grain diameter of the powder obtained after secondary crushing and screening is 50-120 mu m. In step 302, the mass of the irregular hydrogenated and dehydrogenated titanium powder is 50-1000 g; the mass ratio of the zirconia balls to the hydrogenated and dehydrogenated titanium powder is 0.5-2: 1; the diameters of the zirconia balls are respectively 6mm and 3mm, and the ratio of the zirconia balls with the diameters of the two is 1: 1; the flow rate of the argon is 1-1.5L/min, and the aeration time is 30-60 min. In step S303, the temperature rise rate of the rotary furnace is 5-10 ℃/min, and the temperature rises to 300-; the rotating speed of the rotary furnace is 30-60rpm, and the rotating time is 5-10 h; the flow rate of the argon is 1-1.5L/min.

The preparation of the titanium substrate according to the invention is described in detail below with reference to the specific examples:

example 1

Preparing titanium powder for powder hot isostatic pressing near-net forming by adopting high-temperature ball milling: cleaning waste residual titanium by using an oil removing agent to remove surface oil stains, then carrying out acid cleaning treatment by using a mixed solution of 10% HCl and 10% HF, and drying after acid cleaning; mixing the dried waste residual titanium with calcium hydride and magnesium hydride, putting the mixture into a rotary furnace, vacuumizing the rotary furnace, heating the rotary furnace to 600 ℃, keeping the temperature for 30min, introducing high-purity argon to 0.5MPa, and keeping the pressure for 10 h; cleaning the hydrogen-absorbed materials with distilled water and 10% HCl in sequence and drying; then, mechanically crushing the materials under the protection of inert gas; dehydrogenating the crushed material in a vacuum furnace at 600 ℃ for 10 hours; finally, irregular hydrogenated dehydrogenated titanium powder with the grain diameter of 50-120 mu m is obtained through secondary crushing and screening (see figure 4).

Respectively weighing 200g of the irregular hydrogenated and dehydrogenated Ti-6Al-4V powder, 200g of zirconia balls with the diameter of 6mm and 200g of zirconia balls with the diameter of 3mm, uniformly mixing the powders, putting the powders into a high-temperature ball milling tank 2, and fixing the high-temperature ball milling tank 2 in a furnace tube 1 of a rotary furnace by using screws. Continuously and stably introducing argon Ar into the left end and the right end of the self-rotating furnace tube 1 at a flow rate of 1.5L/min, discharging all air in the rotating furnace tube 1 and the high-temperature ball-milling tank 2 after 30min, opening a heating system of the rotating furnace, and heating to 600 ℃ at a heating rate of 5 ℃/min; then, a rotating system of the rotary furnace is opened to enable the rotary furnace tube 1 to rotate at the speed of 30rpm, high-temperature ball milling treatment is carried out for 5 hours, and Ar is continuously and stably introduced at the flow rate of 1.5L/min in the whole process; closing a heating system and a rotating system of the rotary furnace after the ball milling is finished, cooling the powder along with the furnace, and continuously and stably introducing Ar at the flow rate of 1.5L/min in the whole process; cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank 2, taking out titanium powder and zirconia balls from the tank body 5, separating, screening to obtain nearly spherical powder with the particle size of 50-65 μm, drying, and carrying out vacuum packaging; repeating the ball milling step for multiple times to obtain enough powder, uniformly mixing the powder obtained multiple times, drying, and carrying out vacuum packaging and storage. A small amount of powder was taken before packaging, the morphology of the hydrogenated titanium dehydrogenated powder after high temperature ball milling treatment was observed by a scanning electron microscope (see fig. 5), and the fluidity and oxygen content thereof were tested to obtain the oxygen increment of the treated powder, and the results are shown in table 1.

The metal sheath for hot isostatic pressing is sleeved in alcohol for ultrasonic cleaning,removing dust and oil stains on the surface, and drying the cleaned sheath; sealing and welding the upper end cover, the lower end cover and the exhaust pipe with the cylinder by adopting an argon arc welding machine; visually inspecting the welded sheath, and checking whether the welding seam has the defects of slag inclusion, cracks, incomplete fusion, penetration, air holes and the like; then further performing airtightness check by using helium leak detector (leak rate of less than 1.0 × 10 in vacuum mode) ^-9 Pa.m ³ When the pressure is/s, the sheath has good air tightness and meets the use requirement); filling the sieved and obtained 50-65 mu m subsphaeroidal titanium alloy powder into a ladle with good air tightness by adopting a vibration method, and fully vibrating to ensure the filling of the ladle; after the powder is filled, vacuumizing the sheath by a sheath thermal degassing system, specifically, vacuumizing the sheath to a vacuum degree of 1.0 x 10 at room temperature ^-3 Pa below, heating the jacket in a well-type heating furnace to 550 deg.C to reach a vacuum degree of 1.0 × 10 ^-3 Keeping for 5 hours after Pa is lower than the standard value; after vacuumizing, sealing and welding the vacuumizing tube by using a hydraulic clamp matched with argon arc welding; then placing the vacuum-pumped and seal-welded sheath into a hot isostatic pressing furnace, raising the temperature and the pressure to 800 ℃ and 120MPa, and preserving the heat and the pressure for 5 hours at the temperature and the pressure; and (3) after the pressure maintaining is finished, releasing the pressure, cooling the titanium base part in a furnace to be below 200 ℃, taking out the titanium base part, and testing the compactness, the tensile strength and the elongation of the titanium base part, wherein the results are shown in table 1.

Example 2

Cleaning waste residual titanium by using an oil removing agent to remove surface oil stains, then carrying out acid cleaning treatment by using a mixed solution of 10% HCl and 10% HF, and drying after acid cleaning; mixing the dried waste residual titanium with calcium hydride and magnesium hydride, putting the mixture into a rotary furnace, vacuumizing the rotary furnace, heating the rotary furnace to 800 ℃, keeping the temperature for 30min, introducing high-purity argon to 0.1MPa, and keeping the pressure for 10 h; cleaning the materials subjected to hydrogen absorption treatment by distilled water and 10% HCl in sequence and drying; then, mechanically crushing the materials under the protection of inert gas; dehydrogenating the crushed material in a vacuum furnace at 700 ℃ for 8 h; and finally, obtaining irregular hydrogenated dehydrogenated titanium powder with the grain size of 50-120 mu m by secondary crushing and screening, and using the irregular hydrogenated dehydrogenated titanium powder for preparing powder hot isostatic pressing near-net forming by high-temperature ball milling.

Respectively weighing 500g of the irregular hydrogenated and dehydrogenated Ti-6Al-4V powder, 500g of zirconia balls with the diameter of 6mm and 500g of zirconia balls with the diameter of 3mm, uniformly mixing the powders, putting the powders into a high-temperature ball milling tank 2, and fixing the ball milling tank in a furnace tube 1 of a rotary furnace by using screws. Continuously and stably introducing Ar into the left end and the right end of the self-rotating furnace tube 1 at a flow rate of 1L/min, discharging all air in the rotating furnace tube 1 and the high-temperature ball-milling tank 2 after 60min, opening a heating system of the rotating furnace, and heating to 550 ℃ at a temperature rise rate of 5 ℃/min; then, a rotating system of the rotary furnace is opened to enable the rotary furnace tube 1 to rotate at the speed of 50rpm, high-temperature ball milling treatment is carried out for 6h, and Ar is continuously and stably introduced at the flow rate of 1L/min in the whole process; closing a heating system and a rotating system of the rotary furnace after the ball milling is finished, cooling the powder along with the furnace, and continuously and stably introducing Ar at the flow rate of 1L/min in the whole process; after cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank 2, taking out the titanium powder and the zirconia balls from the tank body 5, separating, screening to obtain powder with the particle size of 100-115 mu m, drying and then carrying out vacuum packaging; repeating the ball milling step for multiple times to obtain enough powder, uniformly mixing the powder obtained for multiple times, drying, and packaging and storing in vacuum. A small amount of powder is taken before packaging, the morphology of the hydrogenated titanium dehydrogenated powder after high-temperature ball milling treatment is observed through a scanning electron microscope, the fluidity and the oxygen content of the powder are tested, so that the oxygen increment of the treated powder is obtained, and the result is shown in Table 1.

Ultrasonically cleaning a metal sheath for hot isostatic pressing in alcohol to remove dust and oil stains on the surface, and drying the cleaned sheath; sealing and welding the upper end cover, the lower end cover and the exhaust pipe with the cylinder by adopting an argon arc welding machine; visual inspection is carried out on the welded sheath, and whether the welding seam has the defects of slag inclusion, cracks, incomplete fusion, penetration, air holes and the like is checked; then further performing airtightness check by using helium leak detector (leak rate of less than 1.0 × 10 in vacuum mode) ^-9 Pa.m ³ In the time of/s, the sheath has good air tightness and meets the use requirement); packing the sieved and 100-115 mu m subsphaeroidal titanium alloy powder into a ladle with good air tightness by adopting a vibration method, and fully vibrating to ensure the filling of the ladle; after powder filling is finished, vacuumizing the sheath through a sheath thermal degassing systemSpecifically, first, the jacket is evacuated at room temperature to a vacuum of 1.0X 10 ^-3 Pa below, heating the jacket in a well-type heating furnace to 550 deg.C to reach a vacuum degree of 1.0 × 10 ^-3 Keeping for 5 hours after Pa is lower than the standard value; after vacuumizing, sealing and welding the vacuumizing tube by using a hydraulic clamp matched with argon arc welding; then putting the vacuum-pumped and seal-welded sheath into a hot isostatic pressing furnace, raising the temperature and the pressure to 850 ℃ and 130MPa, and preserving the heat and the pressure for 3 hours at the temperature and the pressure; and (3) after the pressure maintaining is finished, releasing the pressure, cooling the furnace to below 200 ℃, taking out the workpiece, and testing the density, tensile strength and elongation of the workpiece, wherein the results are shown in table 1.

Example 3

Cleaning waste residual titanium by using an oil removing agent to remove surface oil stains, then carrying out acid cleaning treatment by using a mixed solution of 10% HCl and 10% HF, and drying after acid cleaning; mixing the dried waste residual titanium with calcium hydride and magnesium hydride, putting the mixture into a rotary furnace, vacuumizing the rotary furnace, heating the rotary furnace to 700 ℃, keeping the temperature for 30min, introducing high-purity argon to 0.3MPa, and keeping the pressure for 10 h; cleaning the hydrogen-absorbed materials with distilled water and 10% HCl in sequence and drying; then, mechanically crushing the materials under the protection of inert gas; dehydrogenating the crushed material in a vacuum furnace at 700 ℃ for 10 hours; and finally, obtaining irregular hydrogenated dehydrogenated titanium powder with the grain size of 50-120 mu m by secondary crushing and screening, and using the irregular hydrogenated dehydrogenated titanium powder for preparing powder hot isostatic pressing near-net forming by high-temperature ball milling.

Respectively weighing 100g of the hydrogenated and dehydrogenated Ti-6Al-4V powder with irregular morphology, 100g of zirconia balls with the diameter of 6mm and 100g of zirconia balls with the diameter of 3mm, uniformly mixing, putting the mixture into a high-temperature ball milling tank 2, and fixing the high-temperature ball milling tank 2 in a furnace tube 1 of a rotary furnace by using screws. Continuously and stably introducing Ar into the left end and the right end of the self-rotating furnace tube 1 at a flow rate of 1L/min, discharging all air in the rotating furnace tube 1 and the high-temperature ball-milling tank 2 after 60min, opening a heating system of the rotating furnace, and heating to 450 ℃ at a temperature rise rate of 5 ℃/min; then, a rotating system of the rotary furnace is opened to enable the furnace tube to rotate at the speed of 30rpm, high-temperature ball milling treatment is carried out for 8h, and Ar is continuously and stably introduced at the flow rate of 1L/min in the whole process; closing a heating system and a rotating system of the rotary furnace after the ball milling is finished, cooling the powder along with the furnace, and continuously and stably introducing Ar at the flow rate of 1L/min in the whole process; cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank 2, taking out titanium powder and zirconia balls from the tank body 5, separating, screening to obtain powder with the particle size of 60-75 mu m, drying, and carrying out vacuum packaging; repeating the ball milling step for multiple times to obtain enough powder, uniformly mixing the powder obtained multiple times, drying, and carrying out vacuum packaging and storage. A small amount of powder is taken before packaging, the morphology of the hydrogenated titanium dehydrogenated powder after high-temperature ball milling treatment is observed through a scanning electron microscope, the fluidity and the oxygen content of the powder are tested, so that the oxygen increment of the treated powder is obtained, and the result is shown in Table 1. Repeating the steps for many times to prepare sufficient raw material powder for hot isostatic pressing.

Carrying out ultrasonic cleaning on a metal sheath for hot isostatic pressing in alcohol to remove dust and oil stains on the surface, and drying the cleaned sheath; sealing and welding the upper end cover, the lower end cover and the exhaust pipe with the cylinder by adopting an argon arc welding machine; visual inspection is carried out on the welded sheath, and whether the welding seam has the defects of slag inclusion, cracks, incomplete fusion, penetration, air holes and the like is checked; then further performing airtightness check by using helium leak detector (leak rate of less than 1.0 × 10 in vacuum mode) ^-9 Pa.m ³ In the time of/s, the sheath has good air tightness and meets the use requirement); filling the sieved and 60-75 mu m subsphaeroidal titanium alloy powder into a ladle with good air tightness by adopting a vibration method, and fully vibrating to ensure the filling of the ladle; after the powder is filled, the sheath is vacuumized by a sheath thermal degassing system, specifically, the sheath is vacuumized at room temperature until the vacuum degree is 1.0 multiplied by 10 ^-3 Pa below, heating the jacket in a well-type heating furnace to 550 deg.C to reach a vacuum degree of 1.0 × 10 ^-3 Keeping for 5 hours after Pa is lower than the standard value; after the vacuumizing is finished, sealing and welding the vacuumizing tube by using a hydraulic clamp matched with argon arc welding; then placing the vacuum-pumped and seal-welded sheath into a hot isostatic pressing furnace, raising the temperature and the pressure to 950 ℃ and 130MPa, and preserving the heat and the pressure for 3 hours at the temperature and the pressure; and (3) after the pressure maintaining is finished, releasing the pressure, cooling the workpiece in a furnace to below 200 ℃, taking out the workpiece, and testing the density, tensile strength and elongation of the workpiece, wherein the results are shown in table 1.

Example 4

Cleaning waste residual titanium by using an oil removing agent to remove surface oil stains, then carrying out acid cleaning treatment by using a mixed solution of 10% HCl and 10% HF, and drying after acid cleaning; mixing the dried waste residual titanium with calcium hydride and magnesium hydride, putting the mixture into a rotary furnace, vacuumizing, heating to 700 ℃, keeping the temperature for 30min, introducing high-purity argon to 0.5MPa, and keeping the pressure for 5 h; cleaning the hydrogen-absorbed materials with distilled water and 10% HCl in sequence and drying; then, mechanically crushing the materials under the protection of inert gas; dehydrogenating the crushed material in a vacuum furnace at 600 ℃ for 15 hours; and finally, obtaining irregular hydrogenated dehydrogenated titanium powder with the grain size of 50-120 mu m by secondary crushing and screening, and using the irregular hydrogenated dehydrogenated titanium powder for preparing powder hot isostatic pressing near-net forming by high-temperature ball milling.

Respectively weighing 1000g of the irregular hydrogenated and dehydrogenated Ti-6Al-4V powder, 1000g of zirconia balls with the diameter of 6mm and 1000g of zirconia balls with the diameter of 3mm, uniformly mixing the powders, putting the powders into a high-temperature ball milling tank 2, and fixing the high-temperature ball milling tank 2 in a furnace tube 1 of a rotary furnace by using screws. Continuously and stably introducing Ar into the left end and the right end of the self-rotating furnace tube 1 at a flow rate of 1.5L/min, discharging all air in the rotating furnace tube 1 and the high-temperature ball-milling tank 2 after 30min, opening a heating system of the rotating furnace, and heating to 300 ℃ at a temperature rise rate of 5 ℃/min; then, a rotating system of the rotary furnace is opened to enable the furnace tube to rotate at the speed of 60rpm, high-temperature ball milling treatment is carried out for 10 hours, and Ar is continuously and stably introduced at the flow rate of 1.5L/min in the whole process; closing a heating system and a rotating system of the rotary furnace after the ball milling is finished, cooling the powder along with the furnace, and continuously and stably introducing Ar at the flow rate of 1.5L/min in the whole process; cooling to room temperature, stopping ventilation, taking out the high-temperature ball milling tank 2, taking out the titanium powder and the zirconia balls from the tank body 5, separating, screening to obtain powder with the particle size of 75-90 mu m, drying, and carrying out vacuum packaging and storage; repeating the ball milling step for multiple times to obtain enough powder, uniformly mixing the powder obtained multiple times, drying, and carrying out vacuum packaging and storage. A small amount of powder is taken before packaging, the morphology of the hydrogenated titanium dehydrogenated powder after high-temperature ball milling treatment is observed through a scanning electron microscope, the fluidity and the oxygen content of the powder are tested, so that the oxygen increment of the treated powder is obtained, and the result is shown in Table 1. Repeating the steps for many times to prepare sufficient raw material powder for hot isostatic pressing.

Ultrasonically cleaning a metal sheath for hot isostatic pressing in alcohol to remove dust and oil stains on the surface, and drying the cleaned sheath; sealing and welding the upper end cover, the lower end cover and the exhaust pipe with the cylinder by adopting an argon arc welding machine; visual inspection is carried out on the welded sheath, and whether the welding seam has the defects of slag inclusion, cracks, incomplete fusion, penetration, air holes and the like is checked; then further performing airtightness check by using helium leak detector (leak rate of less than 1.0 × 10 in vacuum mode) ^-9 Pa.m ³ In the time of/s, the sheath has good air tightness and meets the use requirement); packing the screened subsphaeroidal titanium alloy powder with the particle size of 75-90 mu m into a ladle with good air tightness by adopting a vibration method, and fully vibrating to ensure the filling of the ladle; after the powder is filled, the sheath is vacuumized by a sheath thermal degassing system, specifically, the sheath is vacuumized at room temperature until the vacuum degree is 1.0 multiplied by 10 ^-3 Pa below, heating the jacket in a well-type heating furnace to 550 deg.C to reach a vacuum degree of 1.0 × 10 ^-3 Keeping for 5 hours after Pa is lower than the standard value; after the vacuumizing is finished, sealing and welding the vacuumizing tube by using a hydraulic clamp matched with argon arc welding; then placing the vacuum-pumped and seal-welded sheath into a hot isostatic pressing furnace, raising the temperature and the pressure to 1000 ℃ and 80MPa, and preserving the heat and the pressure for 4 hours at the temperature and the pressure; and (3) after the pressure maintaining is finished, releasing the pressure, cooling the furnace to below 200 ℃, taking out the workpiece, and testing the density, tensile strength and elongation of the workpiece, wherein the results are shown in table 1.

TABLE 1

Group of	Example 1	Example 2	Example 3	Example 4
					Irregular hydrogenated dehydrogenated titanium powder oxygen content/ppm	1200	1200	1200	1200
Oxygen content/ppm of titanium powder after high-temperature ball milling	1300	1500	1400	1400
					Oxygen increase/ppm	100	300	200	200
Fluidity/(s/50 g)	36	34	30	33
					Density/degree of finished part	99.34	99.56	99.92	99.68
Tensile strength/MPa of finished part	873.9	921.4	980.5	946.8
					Tensile plasticity/% of the finished part	16.1	15.4	17.1	14.3

As can be seen from Table 1, the oxygen increasing amount of the titanium powder after the high-temperature ball milling and shaping treatment in examples 1-4 is extremely low, and is in the range of 100-300ppm, and the powder fluidity is 30-36s/50g, so that the requirements of the raw material powder for hot isostatic pressing can be met. The high-temperature ball milling process has the advantages of low cost, simple process and equipment, controllable oxygen content, high powder yield and the like, and is beneficial to large-scale application of hot isostatic pressing for manufacturing titanium products; in addition, the method can be applied to the shaping treatment of other metal powder, and the metal powder for powder near-net forming technology such as additive manufacturing, injection molding and the like is produced. The parts prepared by the hot isostatic pressing method in examples 1-4 have high density, high strength and high plasticity, and the density is higher than 99%. In examples 2-4, the strength and elongation of the article are respectively in the range of 921.4MPa-980.5MPa and 14.3% -17.1%, which are both higher than the American ASTM-B381 standard forged Ti-6Al-4V alloy (895MPa, 10%); the tensile strength of the article in example 1 was 873.9MPa, which is similar to ASTM-B381 standard wrought Ti-6Al-4V alloy, but the elongation 16.1% is significantly higher than that of the wrought Ti-6Al-4V alloy. In conclusion, the low-cost high-performance titanium-based part hot isostatic pressing preparation method provided by the invention has a wide application prospect, and can meet the requirements of light high-strength high-temperature-resistant materials for aerospace.

The irregular hydrogenated dehydrogenated titanium powder is prepared by taking waste residual titanium as a raw material, on the basis, the high-temperature ball milling technology is adopted based on the thermoplastic deformation principle, the cost reduction of the titanium powder for powder hot isostatic pressing is realized, and finally the high-performance titanium alloy part is prepared by the hot isostatic pressing technology. Compared with the prior art that titanium ore is used as a raw material and pure titanium is prepared by methods such as smelting, the method for preparing hydrogenated and dehydrogenated titanium powder by using waste residual titanium as a raw material is more energy-saving and environment-friendly. Meanwhile, compared with spherical powder preparation technologies such as an air atomization method, a plasma spheroidization method and the like, the high-temperature ball milling technology has the advantages of simple process equipment, low cost, high powder yield and better shaping effect compared with common mechanical ball milling, reduces the intrinsic strength of the titanium powder at high temperature, and is more favorable for plastic deformation and welding and agglomeration among small particles; in addition, the method can be used for low-cost preparation of other high-value powder hot isostatic pressing raw material powder and powder required by the fields of powder injection molding, additive manufacturing and the like. The adopted powder hot isostatic pressing near net shaping (NNS-HIP) process is relatively simple, the process period is short, the material utilization rate is high, the formed workpiece is uniform and fine in structure, the performance can reach or even exceed the level of a forge piece, and the high-performance and high-precision integrated thin-wall deep-hole shell and other deep-cavity barrel complex components can be prepared.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A hot isostatic pressing preparation method of a titanium substrate is characterized by comprising the following steps:

s300, filling the screened and dried subsphaeroidal titanium alloy powder into the metal sheath with good air tightness by adopting a vibration method, and fully vibrating to ensure that the metal sheath is filled;

2. The method for hot isostatic pressing of titanium substrates of claim 1, further comprising the steps of:

3. The process for hot isostatic pressing of titanium substrates according to claim 1 or 2, wherein in step S200, the metal capsule has a gas-tight compliance with a vacuum mode leak rate of less than 1.0 x 10 ^-9 Pa.m ³ /s。

4. The method for hot isostatic pressing of titanium substrates according to claim 1 or 2, wherein in step S400, the metal capsule is evacuated using a capsule thermal degassing system, further comprising:

s401, vacuumizing the metal sheath to the vacuum degree of 1.0 x 10 at room temperature ^-3 Pa below; and

s402, placing the metal sheath into a well type heating furnace to be heated to 550 ℃, and enabling the vacuum degree to reach 1.0 multiplied by 10 ^-3 After Pa is below, the reaction is kept for 5 h.

5. The method for hot isostatic pressing of titanium substrates according to claim 1 or 2, wherein in step S500, the set temperature is 800-.

6. The method for hot isostatic pressing of titanium substrates according to claim 1 or 2, wherein the near-spherical titanium-based powder in step S300 is prepared by:

s303, after the air in the furnace tube of the rotary furnace and the high-temperature ball milling tank is completely discharged, opening a heating system of the rotary furnace, heating to a set temperature at a set heating rate, opening the rotary system of the rotary furnace, carrying out ball milling at a set rotating speed at a constant temperature, and continuously and stably introducing argon in the whole process at the set speed;

7. The method for hot isostatic pressing of titanium-based articles according to claim 6, wherein in step S301, the cleaning agent is a degreasing agent and a mixed solution of 10% HCl and 10% HF, the reducing agent for hydrogenation reduction is calcium and magnesium hydride, the reduction temperature is 600-; cleaning the hydrogen absorption material by using distilled water and a 10% HCl solution in sequence; the dehydrogenation temperature is 600-700 ℃, the time is 5-30h, and the grain diameter of the powder obtained after secondary crushing and screening is 50-120 mu m.

8. The method for hot isostatic pressing of titanium substrates of claim 6, wherein in step 302, the mass of said irregular hydrogenated dehydrogenated titanium powder is 50-1000 g; the mass ratio of the zirconia balls to the hydrogenated and dehydrogenated titanium powder is 0.5-2: 1; the diameters of the zirconia balls are respectively 6mm and 3mm, and the ratio of the zirconia balls with the diameters is 1: 1; the flow rate of the argon is 1-1.5L/min, and the aeration time is 30-60 min.

9. The method for hot isostatic pressing of titanium-based articles according to claim 6, wherein in step S303, the temperature rise rate of the rotary furnace is 5-10 ℃/min, and the temperature rises to 300-600 ℃; the rotating speed of the rotary furnace is 30-60rpm, and the rotating time is 5-10 h; the flow rate of the argon is 1-1.5L/min.

10. A titanium substrate prepared by the process for hot isostatic pressing of a titanium substrate according to any one of claims 1 to 9.