Preparation method of tungsten-cobalt-nickel-titanium-based alloy

Abstract

The invention discloses a preparation method of a tungsten-cobalt-nickel-titanium-based alloy, which comprises tungsten powder, cobalt powder, nickel powder and titanium powder, and comprises the following steps: step A, mixing raw materials according to a weight ratio and filling the mixture into a ball mill, step B, screening the mixture and precipitating; step C, drying the precipitated slurry; step D, screening the cooled dried powder; step E, adding a proper amount of a forming agent; step F, putting the mixture containing the synthetic agent into a vibration crushing screening machine, and uniformly screening; step G, putting the mixture into a granulator for granulating and forming; step H, storing after drying; step I, sintering in a vacuum furnace and preserving heat; and J, surface oxide layer treatment is carried out after cooling and discharging. The process is simple, the machining efficiency can be improved, the machined alloy has high shock resistance, pressure resistance, corrosion resistance, breakage resistance and the like and has more uniform flowability, it is guaranteed that the stress density around a product is more uniform during pressing, and the machining cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy processing, and in particular relates to a method for preparing a tungsten-cobalt-nickel-titanium based alloy. Background Art

[0002] Cemented carbide is an alloy material made from a hard compound of refractory metals and a bonding metal through a powder metallurgy process. It has excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance, and corrosion resistance. Tungsten-cobalt-nickel-titanium-based alloy is a new technology and new material, mainly used for CNC tool gaskets on CNC tool bars. However, the conventional processing technology of this alloy is relatively complicated and the processing cost is high, which makes it difficult to meet market demand. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing a tungsten-cobalt-nickel-titanium based alloy.

[0004] The technical solution for achieving the purpose of the present invention is a method for preparing a tungsten-cobalt-nickel-titanium based alloy, comprising tungsten powder, cobalt powder, nickel powder and titanium powder, comprising the following steps:

[0005] Step A: The above raw materials are mixed in a certain weight ratio and loaded into a ball mill, and an appropriate amount of alloy balls and ball milling liquid are added to perform ball milling operation;

[0006] Step B, screening and settling the mixture after ball milling in step A using a sieve;

[0007] Step C: placing the precipitated slurry in step B into a vacuum dryer for drying;

[0008] Step D, screening the cooled dried powder;

[0009] Step E: Add an appropriate amount of forming agent to a certain weight of powder and put it into a glue mixing machine. After mixing for a certain period of time, pour the powder into a stainless steel plate and dry it naturally;

[0010] Step F, placing the mixture containing the forming agent in step E on a vibrating sieve to be screened evenly;

[0011] Step G, placing the raw materials in step F into a granulator and uniformly rolling and granulating them;

[0012] Step H, storing after drying;

[0013] Step I: Place the material from step H into a vacuum furnace and sinter to 1430-1470 degrees Celsius and keep warm;

[0014] Step J: After cooling to 110 degrees and taking it out of the furnace, the surface oxide layer is treated and double-sided fine grinding is performed.

[0015] More preferably, the invention further comprises iron powder or stainless steel powder.

[0016] The weight proportions of the tungsten powder, cobalt powder, nickel powder, titanium powder and iron powder or stainless steel powder are as follows:

[0017] Tungsten powder: 30%-40%;

[0018] Cobalt powder: 2%-3%;

[0019] Nickel powder: 10%-20%;

[0020] Titanium powder: 35%-45%;

[0021] Iron powder or stainless steel powder: 6%-8%. The sum of the mass percentages of the above components is 100%.

[0022] Alternatively, preferably, the weight proportions of the tungsten powder, cobalt powder, nickel powder and titanium powder are:

[0023] Tungsten powder: 30%-40%;

[0024] Cobalt powder: 2%-3%;

[0025] Nickel powder: 16%--28%;

[0026] Titanium powder: 35%-45%. The sum of the mass percentages of the above components is 100%.

[0027] Further preferably, in step A, the ball milling solution is methanol or ethanol with a concentration of not less than 96%;

[0028] The alloy balls use 3.3-4.3 kg for 1L ball milling space;

[0029] The weight ratio of the ball milling liquid to the mixed raw materials is 25-35kg:100kg.

[0030] The ball milling time in step A is 45-48 hours.

[0031] More preferably, in step B, the sieve is a 320-mesh sieve.

[0032] Further preferably, in step C, the drying time in the vacuum dryer is 21-24 hours, the temperature is 100-130 degrees, and the vacuum degree is 0.4-1 MPa.

[0033] More preferably, in the step D, the screening is performed by transferring the material to an automatic vibrating crusher and using a sieve of 50 to 70 meshes.

[0034] It is further preferred that: in the step E, the molding agent comprises a mixture of solvent oil and a saturated linear polymer;

[0035] The amount of powder and molding agent added is 40kg of powder using 5600L-6300L of molding agent. After stirring and mixing in a glue mixer for 3-4 minutes, pour the powder into a stainless steel tray and dry it naturally for 8-20 minutes.

[0036] More preferably, in step F, the mixture is placed in an automatic vibrating crusher and sieved through a 50-70 mesh sieve.

[0037] More preferably, in step G, the sieved and uniformly mixed material is loaded into a granulator in batches of about 35 kg and uniformly rolled for granulation for 8-15 minutes. During the granulation process, the angle of the granulation barrel is adjusted in time to make the ratio of coarse, medium and fine powder particles 1:8:1.

[0038] It is further preferred that: in the step E, the molding agent comprises a mixture of solvent oil and a saturated linear polymer;

[0039] The amount of powder and molding agent added is 40kg of powder using 5600L-6300L of molding agent. After stirring and mixing in a glue mixer for 3-4 minutes, pour the powder into a stainless steel tray and dry it naturally for 8-20 minutes.

[0040] More preferably, in step I, the sintering temperature is 1450 degrees, and the holding time is 60 minutes.

[0041] Further preferably, in step J, the surface oxide layer is treated by using an automatic sandblasting machine in combination with corundum sand.

[0042] The present invention has positive effects: the process of the present invention is simple, which is not only conducive to improving processing efficiency, but also the processed alloy has strong shock resistance, pressure resistance, corrosion resistance, and anti-breakage properties. The mixed material particles produced therefrom have more uniform fluidity, and the force density around the product is ensured to be more uniform during pressing, thereby improving the processing quality, reducing the processing cost, and having strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein:

[0044] Figure 1 Schematic diagram of the process steps of the present invention. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] Example 1

[0047] See Figure 1 A method for preparing a tungsten-cobalt-nickel-titanium based alloy, comprising tungsten powder, cobalt powder, nickel powder and titanium powder, comprises the following steps:

[0048] Step A: The above raw materials are mixed in a certain weight ratio and loaded into a ball mill, and an appropriate amount of alloy balls and ball milling liquid are added to perform ball milling. In this embodiment, in step A, the weight proportions of the tungsten powder, cobalt powder, nickel powder and titanium powder are as follows: tungsten powder: 30%-40%; cobalt powder: 2%-3%; nickel powder: 16%-28%; titanium powder: 35%-45%, and the sum of the mass percentages of the above components is 100%.

[0049] And when used, in step A, the ball milling liquid is methanol or ethanol with a concentration of not less than 96%; the alloy balls use 3.3-4.3 kg for 1L ball milling space; the weight ratio of the ball milling liquid to the mixed raw materials is 25-35 kg:100 kg, the mixed ball milling is carried out for 24 hours to take quality index testing, and then wet milling is carried out for 21-24 hours, and the ball milling time in step A is 45-48 hours.

[0050] Step B: Screen and precipitate the mixture after ball milling in Step A. In this embodiment, the sieve in Step B is a 320-mesh sieve. The sieved material is allowed to settle for 24 hours, and then the methanol or ethanol is drained. The alloy mixture powder in a solid-liquid state is placed in a vacuum dryer.

[0051] Step C: Place the precipitated slurry from Step B into a vacuum dryer for drying; the drying time is 21-24 hours. In Step C, the drying time in the vacuum dryer is 21-24 hours, and the temperature is 100-130 degrees Celsius, with a vacuum degree of 0.4-1 MPa. The alloy mixture powder is fully dried to remove moisture under vacuum. The mixture is then cooled with circulating water or cooling water for at least 12 hours, until the temperature of the vacuum-dried alloy mixture powder is within the range of -40°C to 20°C. The mixture is then removed from the pot and placed in a sealed stainless steel barrel. The mixture is then transferred to a semi-finished powder warehouse for further cooling for at least 48 hours. The warehouse maintains a 24-hour constant temperature of 22-26°C and a humidity of 45-60°C.

[0052] Step D, screening the cooled dried powder; in the step D, the sieving is transferred to an automatic vibrating crusher and sieved through a 50-70 mesh screen to make the particles more uniform.

[0053] Step E: Add an appropriate amount of molding agent to a certain weight of powder, load it into a glue mixer, mix it for a certain period of time, and then pour it into a stainless steel tray to dry naturally. In this embodiment, in step E, the molding agent includes a mixture of solvent oil and a saturated linear polymer. The amount of molding agent added to 40 kg of powder is 5600 L to 6300 L. After stirring and mixing in the glue mixer for 3 to 4 minutes, pour it into a stainless steel tray and dry naturally for 8 to 20 minutes.

[0054] After mixing evenly in the glue mixing machine, pour it into professional stainless steel trays, each tray weighs 35±5kg.

[0055] Step F: Place the mixture containing the forming agent in step E on a vibrating sieve and sieve it evenly; transfer it to an automatic vibrating sieve and sieve it through a 50-70 mesh screen. The mixture is half granule and half powder and is then loaded into a granulator.

[0056] Step G, put the raw materials in step F into the granulator and roll them evenly for granulation; in step G, the sieved and evenly mixed material in step F is loaded into the granulator in batches of about 35 kg and rolled evenly for 8 to 15 minutes. During the granulation process, the angle of the granulation barrel should be adjusted in time, and the controllable range should be 35-50 degrees to ensure that the ratio of coarse, medium and fine powder particles is 1:8:1. The mixed powder has a Fisher particle size of less than 1 micron, which is a fine particle; 1-8 microns are medium particles; and larger than 8 microns are coarse particles. Check whether the particle size is uniform and test whether the fluidity of the particles is normal. The loose density of the powder particles is 1.70 to 2.00 g / cm 3 .

[0057] Step H: After drying and storage: The uniformly granulated mixture is placed in stainless steel trays, each weighing 35±5 kg. The mixture is placed in an oven and dried for 25 to 40 minutes at a temperature of 95 to 105 degrees Celsius. The powder is frequently stirred during drying. The mixture is then removed from the oven and placed on a cart to cool naturally to normal temperature. The mixture is then inverted into a barrel and the barrel lid is sealed.

[0058] After the above procedures are completed, the finished powder will be put into storage in the pressing workshop and the powder warehouse will maintain a constant temperature of 24 to 26 degrees for 24 hours.

[0059] Step I, put the material of step H into a vacuum furnace and sinter it to 1430-1470 degrees and keep it warm; in step I, the sintering is to 1450 degrees, and the holding time is 60 minutes. In this embodiment, it can use refined mold support, and perform preliminary processing on the mold through slow wire cutting, mirror electric pulse, etc. In order to improve product quality, the gap between the punch and the mold cavity can be required to be no more than 0.01mm. During the mold matching process, use ultra-fine diamond adhesive paste and continue to polish until the mold wall is smooth and flawless. The mold cavity is smooth so that the product is evenly charged to achieve density balance. The charging amount is calculated based on the product size volume × powder density. The pressing weight is the charging amount plus the volume multiplied by the base number 0.015±0.003, fully considering the volatilization of the medium and moisture during the sintering process.

[0060] The boats used are made of ultra-fine graphite particles, which offer the advantage of uniform thermal conductivity. The boats are coated with a special carbide coating to prevent product adhesion to the boat. The boat's superior thermal conductivity ensures uniform heat distribution, resulting in a refined internal structure and minimizing the presence of bubbles.

[0061] To avoid curved surfaces on CNC knife gaskets, the boat size and loading placement are designed to ensure even heating of the surface. Therefore, the low-temperature zone is within 0-300 degrees Celsius, and the original 80-minute sintering time is adjusted to 70 minutes, with a 20-minute hold. The liquid sintering process has been improved, increasing the temperature from 1150°C by 1.5-2.0°C / minute to 1350°C to maximize liquid fusion. In the high vacuum and high temperature, the carbide alloy particles are maximized, allowing them to fully expand, thereby changing the particle state, perfecting the physical structure, and increasing strength.

[0062] Vacuum control: In the low temperature zone between 300-580 degrees, argon is injected to control the vacuum degree at 1500kpa and extend the holding time for 120 minutes to allow the mixture in the product to be completely discharged out of the furnace. During high vacuum and high temperature liquid sintering, there is also the loss of cobalt and nickel content, so the vacuum is controlled to ensure that the loss of cobalt and nickel affects the product quality. Make full use of the effect of vacuum. Therefore, during the sintering process of CNC knife gasket alloy products, the loss of cobalt and nickel is protected during the high vacuum and high temperature liquid phase sintering at 1350-1450 degrees. The vacuum degree is reduced and argon is filled in the furnace, and the vacuum is reduced from 5-10kpa to 1500-2000kpa until the temperature drops. This protects the cobalt and nickel content in the product from loss to the greatest extent. In addition, the high temperature and low vacuum state also protects the product from oxidation.

[0063] Step J: After cooling to 110 degrees and taking out of the furnace, the surface oxide layer is treated and double-sided fine grinding is performed. In step J, the surface oxide layer is treated by an automatic sandblasting machine with corundum sand.

[0064] The double-sided fine grinding is the double-sided fine grinding of the CNC knife gasket alloy product. The double-end surface fine grinding is performed to control the size to be around plus or minus 0.02s and the flatness to be around 0.01s.

[0065] The product produced in this embodiment has good physical properties: such as hardness (HRA): 87~89 degrees, density (g / cm3): 6.8~7.2, bending strength (N / mm2): 1150~1400, coercive force: 3.0~4.0, and cobalt magnetism: 20~22.

[0066] Example 2

[0067] This embodiment is basically the same as Example 1, except that: in this embodiment, iron powder or stainless steel powder is also provided, and the weight proportions of the tungsten powder, cobalt powder, nickel powder, titanium powder and iron powder or stainless steel powder are as follows: tungsten powder: 30%-40%; cobalt powder: 2%-3%; nickel powder: 10%-20%; titanium powder: 35%-45%; iron powder or stainless steel powder: 6%-8%, and the sum of the mass percentages of the above components is 100%.

[0068] The present invention has positive effects: the process of the present invention is simple, which is not only conducive to improving processing efficiency, but also the processed alloy has strong shock resistance, pressure resistance, corrosion resistance, and anti-breakage properties. The mixed material particles produced therefrom have more uniform fluidity, and the force density around the product is ensured to be more uniform during pressing, thereby improving the processing quality, reducing the processing cost, and having strong applicability.

[0069] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components described in the specification can also be directly processed according to existing technical common sense without any doubt. At the same time, the connection method of each component adopts the mature conventional means in the existing technology, and the machinery, parts and equipment all adopt conventional models in the existing technology, so no specific description is given here.

[0070] Obviously, the above embodiments of the present invention are merely examples for the purpose of illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all embodiments here. However, obvious variations or modifications arising from the essence of the present invention remain within the scope of protection of the present invention.

Claims

1. A method for preparing a tungsten-cobalt-nickel-titanium based alloy, comprising tungsten powder, cobalt powder, nickel powder and titanium powder, characterized in that: The following steps are involved: Step A: The above raw materials are mixed in a certain weight ratio and loaded into a ball mill, and an appropriate amount of alloy balls and ball milling liquid are added to perform ball milling operation; Step B, screening and settling the mixture after ball milling in step A using a sieve; Step C: placing the precipitated slurry in step B into a vacuum dryer for drying; Step D, screening the cooled dried powder; Step E: Add an appropriate amount of forming agent to a certain weight of powder and put it into a glue mixing machine. After mixing for a certain period of time, pour the powder into a stainless steel plate and dry it naturally; Step F, placing the mixture containing the forming agent in step E on a vibrating sieve to be screened evenly; Step G, placing the raw materials in step F into a granulator and uniformly rolling and granulating them; Step H, storing after drying; Step I: Place the material from step H into a vacuum furnace and sinter to 1430-1470 degrees Celsius and keep warm; Step J: After cooling to 110 degrees and taking it out of the furnace, the surface oxide layer is treated and double-sided fine grinding is performed.

2. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, wherein: In step A, iron powder or stainless steel powder is also included.

3. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 2, wherein: The weight proportions of the tungsten powder, cobalt powder, nickel powder, titanium powder and iron powder or stainless steel powder are as follows: Tungsten powder: 30%-40%; Cobalt powder: 2%-3%; Nickel powder: 10%-20%; Titanium powder: 35%-45%; Iron powder or stainless steel powder: 6%-8%. The sum of the mass percentages of the above components is 100%.

4. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, wherein: The weight proportions of the tungsten powder, cobalt powder, nickel powder and titanium powder are as follows: Tungsten powder: 30%-40%; Cobalt powder: 2%-3%; Nickel powder: 16%--28%; Titanium powder: 35%-45%. The sum of the mass percentages of the above components is 100%.

5. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, wherein: In step A, the ball milling solution is methanol or ethanol with a concentration of not less than 96%; The alloy balls use 3.3-4.3 kg for 1L ball milling space; The weight ratio of the ball milling liquid to the mixed raw materials is 25-35kg:100kg. The ball milling time in step A is 45-48 hours.

6. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, wherein: In step B, the sieve is a 320-mesh sieve; In step C, the drying time in the vacuum dryer is 21-24 hours, the temperature is 100-130 degrees, and the vacuum degree is 0.4-1Mpa; In the step D, the screening is performed by transferring the material to an automatic vibrating crusher and using a 50-70 mesh screen.

7. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, characterized in that: In the step E, the molding agent comprises a mixture of solvent oil and a saturated linear polymer; The amount of powder and molding agent added is 40kg powder using 5600L-6300L molding agent, stir and mix in the glue mixing machine for 3-4 minutes, then pour into the stainless steel tray and dry naturally for 8-20 minutes; In the step F, the mixture is placed in an automatic vibrating crusher and sieved through a 50-70 mesh screen.

8. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, characterized in that: In the step G, the sieved and uniformly mixed material is loaded into a granulator in batches of about 35 kg and uniformly rolled for granulation for 8-15 minutes. During the granulation process, the angle of the granulation barrel is adjusted in time to make the ratio of coarse, medium and fine powder particles 1:8:

1.

9. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, wherein: In step I, the sintering temperature is 1450 degrees, and the holding time is 60 minutes.

10. The method for preparing a tungsten-cobalt-nickel-titanium based alloy according to claim 1, characterized in that: In step J, the surface oxide layer is treated by using an automatic sandblasting machine with corundum sand.

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