CN114045424B - Mixed powder for additive manufacturing and preparation method thereof - Google Patents

Abstract

The invention discloses a mixed powder for additive manufacturing and a preparation method thereof. The method realizes high-efficiency and uniform mixing of the powder through vibration, and at the same time ensures the fluidity of the powder, and is used in the additive manufacturing technology. This method is not only suitable for the flexible and simple requirements of powder composition control in scientific research, but also suitable for the high efficiency and large-scale requirements of industrial production. The invention realizes the control of the composition of the powder without changing the original sphericity and fluidity of the powder. For the powder bed additive manufacturing technology, it can not damage the powder spreading quality of the powder, that is, the uniform spreading and high packing density of the powder layer; for the synchronous powder feeding additive manufacturing technology, it can maintain the stability of powder feeding, Reduce the risk of powder nozzle clogging, so as to ensure that the mixed powder meets the formability requirements of additive manufacturing.

Description

A kind of mixed powder for additive manufacturing and preparation method thereof

technical field

The invention belongs to the technical field of additive manufacturing, and in particular relates to a mixed powder for additive manufacturing and a preparation method thereof.

Background technique

Additive manufacturing is a newly developed advanced numerical manufacturing technology, which has been widely used in aerospace, biomedical, automotive and other fields. Powder is the most commonly used raw material method in additive manufacturing technology. For example, the powder of selective laser melting additive manufacturing technology is 15-53 microns, and the powder of electron beam selective laser melting additive manufacturing technology is 45-105 microns. Laser direct The powder of energy deposition technology (or laser stereoforming technology) is 75-200um. When the alloy composition is adjusted to a certain extent or another compound is added to the alloy, one way is to smelt the alloy and then re-powder. This method has a long period of time and high cost, and sometimes it is even impossible to achieve technically. Another way is to mix multiple powders for additive manufacturing, which is straightforward and flexible. At present, powder mixing methods include mechanical mixing, ball milling, chemical plating, etc., and there are problems such as uneven powder mixing, powder deformation that damages the formability of additive manufacturing, or low powder mixing efficiency. Due to the fast forming speed of additive manufacturing, if the powder to be melted Uneven mixing will lead to uneven composition of additive manufacturing samples; powder deformation will reduce powder fluidity and bulk density, which will easily lead to the formation of additive manufacturing forming defects; low powder mixing efficiency will not meet industrial production. Therefore, these powder mixing methods are often difficult to apply to the field of additive manufacturing technology.

On the other hand, existing vibratory mixers are usually aimed at the mixing of liquids and organic powders, and for the mixing of metal powders with high density, usually only 0.1-0.3kg of metal powder can be mixed at a time, and its efficiency is compared with mechanical mixing or ball milling. Without significant advantages, it cannot meet the needs of large-scale applications. Due to the limitation of strength and fatigue life of parts such as springs designed by its mechanical mechanism, existing vibratory mixers cannot improve the efficiency and scale of metal powder mixing by simply amplifying parts and vibration power.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art, and provide a mixed powder for additive manufacturing and its preparation method, to solve the problem of low powder mixing efficiency in the prior art, and the powder after mixing is caused by the composition of the formed sample. Inhomogeneity or technical problems that cause forming defects and are not suitable for the field of additive manufacturing technology.

In order to achieve the above object, the present invention adopts the following technical solutions to achieve:

A mixed powder for additive manufacturing, comprising a composite main powder and an additional powder, the additional powder is dispersed on the surface of the main powder, or a part of the additional powder is infiltrated into the main powder;

The main body powder is aluminum alloy, titanium alloy, high-entropy alloy, steel or superalloy;

The additional powder is metal powder, non-metal elemental powder, carbide, boride or nitride;

The main powder and the additional powder are compounded by mixing and vibrating.

A further improvement of the present invention is:

Preferably, the main powder is micron-scale, and the additional powder is micron-scale or nano-scale.

A method for preparing mixed powder for additive manufacturing, comprising the following steps:

Step 1, put the main powder and the additional powder together in the powder mixing container to form a mixed powder, and place the powder mixing container on the vibrating table body;

Step 2, washing the inside of the powder mixing container;

Step 3, setting the vibration frequency range of the vibrating table body as f _min to f _max , and setting the first acceleration and compression factor;

Step 4, the vibrating table body starts to vibrate from f _min , and the vibration frequency increases with the set first acceleration until it reaches f _max ; during this process, the vibration degree of the mixed powder is observed, and when the vibration degree of the mixed powder is the most intense, record Corresponding frequency; when the vibration degree of the mixed powder is the most intense, the mixed powder is in contact with the upper cover of the mixing container, and the frequency is the optimal frequency f _best or the optimal frequency interval (f ₁ , f ₂ );

Step 5. Set the vibration frequency range of the vibrating table body again. If there is an optimal frequency f _best for the mixed powder, set the residence time. The vibrating table body vibrates at the f _best frequency and stay for the set residence time until The vibration ends; if there is an optimal frequency interval (f ₁ , f ₂ ), set the second acceleration value and the dwell time, the vibrating table body starts to vibrate from f ₁ , and stays at the set speed with the second acceleration value increasing speed Dwelling time, the vibration frequency continues to increase until it reaches f ₂ , and the vibration ends;

Step 6: After the powder mixing is completed, take out the mixed powder and set it aside.

Preferably, in step 1, the powder mixing container and the vibrating table body are fixedly connected.

Preferably, in step 1, the powder mixing container is scrubbed with argon gas, the scrubbing time is 1-3 min, and the scrubbing gas flow rate is 10-30 cm ³ /min.

Preferably, in step 4, if the vibration of the powder is always smooth, f _min and f _max are reset.

Preferably, in step 5, f ₁ =f _best -(5-40)HZ, f ₂ =f _best +(10-40)HZ.

Preferably, in step 5, in the powder mixing process, if there is no f _best , each powder mixing process is that the vibrating table body starts to vibrate from f ₁ , stays for a set dwell time, and increases the speed with the second acceleration value , the vibration frequency continues to increase, each increase in turn, stay for a dwell time until it rises to f ₂ , the vibration ends; if there is f _best , vibrate at this frequency for the set time;

The powder mixing process is repeated several times.

Preferably, a cooling process and a gas washing process are arranged between the two powder mixing processes.

Compared with the prior art, the present invention has the following beneficial effects:

The invention discloses a mixed powder for additive manufacturing. The mixed powder includes a main powder and an additional powder. The main powder and the additional powder are compounded by mixing and vibrating, so that various powders used in additive manufacturing Both can be prepared by this method. After mixing, additional powder will be evenly distributed on the surface of the main body. According to the amount of additional powder added before mixing, there will be certain differences in morphology. The more the additional powder, it can even cover the entire main powder particle; in addition, for some powders (such as soft aluminum alloy powder), the additional powder can be infiltrated into the main powder by this method. The mixed powder prepared by this method is uniform and highly efficient mixed by obtaining the optimal vibration frequency (when vibrating at this frequency, the maximum vibration amplitude of the mixed powder can be achieved) after optimization. The mixed powder can ensure that its fluidity and laser meter yield are similar to the main powder before mixing, and will not affect the quality of the powder.

The invention discloses a method for preparing powder mixing powder for additive manufacturing. The method realizes efficient and uniform mixing of powder through vibration, and at the same time ensures the fluidity of the powder, and is used in additive manufacturing technology. This method is not only suitable for the flexible and simple requirements of powder composition control in scientific research, but also suitable for the high efficiency and large-scale requirements of industrial production. Inflation (inert gas) protection is carried out throughout the vibration process. On the one hand, the inflated gas can reduce the content of reactive gases (such as oxygen) with the alloy powder, ensure that the oxygen content of the powder does not increase, and take away the moisture in the atmosphere , Improve powder mixing effect. Therefore, the invention does not change the original sphericity and fluidity of the powder while realizing the control of the composition of the powder. For the powder bed additive manufacturing technology, it can not damage the powder spreading quality of the powder, that is, the uniform spreading and high packing density of the powder layer; for the synchronous powder feeding additive manufacturing technology, it can maintain the stability of powder feeding, Reduce the risk of powder nozzle clogging, so as to ensure that the mixed powder meets the formability requirements of additive manufacturing. In the subsequent additive manufacturing process, due to the mixing method used in the present invention, uniformly mixed metal powder with high sphericity is obtained, which can improve the fluidity of the powder during the additive manufacturing process, increase the laser absorption rate, and make the paving The powder layer is uniform and flat during the powder process, which can keep the powder bulk density at a high level, improve the stability of powder feeding, and reduce the risk of powder nozzle clogging. In the final formed sample, the generation of voids and defects can be reduced, and the composition of the sample can be made uniform.

Description of drawings

Fig. 1 is a device structural diagram of the present invention;

Fig. 2 is CoCrFeNi high-entropy alloy (particle size 15-53um) mixed with 1wt% WC nanopowder (particle size 30-50nm), wherein (a) CoCrFeNi mixed WC SEM image (b) surface enlarged view;

Fig. 3 is that CoCrFeNi high-entropy alloy (particle size 15-53um) mixes 1wt% TiC nano-powder (particle size 40nm), wherein, (a) is the overall enlarged figure of CoCrFeNi high-entropy alloy mixing 1wt% TiC nano-powder powder particle; ( b) is the distribution map of TiC nanopowder on the surface of CoCrFeNi high entropy alloy.

Figure 4 is CoCrFeNi high entropy alloy (particle size 15-53um) mixed with 1wt% Y ₂ O ₃ nanometer powder (particle size 10-30nm), wherein, (a) is CoCrFeNi high entropy alloy mixed with 1wt% Y ₂ O ₃ nanometer powder The overall enlarged view of powder particles; (b) is the distribution of Y ₂ O ₃ nano-powder on the surface of CoCrFeNi high-entropy alloy.

Figure 5 is IN625 superalloy powder (particle size 15-53um) mixed with 1wt% Y ₂ O ₃ nano powder (particle size 10-30nm), wherein (a) initial IN625 powder, (b) Y ₂ O ₃ nano powder, ( c) Enlarged view of Y ₂ O ₃ nanopowder agglomerates, (d) mixed powder, (e) and (f) energy spectrum scans of powder Y and O elements;

Fig. 6 is the Ti55531 titanium alloy powder (particle size 45-150um) mixed B powder (particle size 100um), wherein, (a) is the macroscopic feature figure of the mixed powder of Ti55531 titanium alloy powder and B powder; (b) is B powder in Distribution map of Ti55531 titanium alloy surface.

Fig. 7 is AlSi10Mg alloy powder (particle diameter 50-150um) mixes 1wt%TiB ₂ nanopowder (average particle diameter 500nm), wherein, (a) is the overall enlarged view of AlSi10Mg alloy powder mixing 1wt%TiB ₂ nanopowder powder particle; (b) is the distribution map of TiB ₂ nanometer powder on the surface of AlSi10Mg.

Among them, 1-cooling fan; 2-vibration table body; 3-powder mixing container; 4-first sensor; 5-power supply; 6-argon gas source; 7-host computer; 8-quick plug; 9-cover ; 10 - base plate; 11 - second sensor.

Detailed ways

The present invention is described in further detail below in conjunction with accompanying drawing:

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, and therefore cannot be construed as limiting the present invention; the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be construed as indicating or implying relative importance; in addition, unless otherwise Clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediary, Can be a communication within two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The invention discloses a mixing device and method for additive manufacturing. Referring to FIG. 1, the mixing device includes a vibrating table body 2, a powder mixing container 3 is arranged on the vibrating table body 2, a powder mixing container 3 and a vibration The platform body 2 is detachably connected.

Specifically, the vibrating table body 2 is fixed with a bottom plate 10, the bottom plate 10 and the powder mixing container 3 are detachably connected, the upper end of the powder mixing container 3 is provided with a cover plate 9, and the cover plate 9 and the bottom plate 10 are aluminum alloy plates . The cover plate 9 and the bottom plate 10 are connected by 8 bolts. Two quick plugs are arranged on the cover plate 9 for connecting with the argon gas source 6 .

The bottom plate 10 is provided with a first sensor 4, and the vibrating table body 2 is provided with a second sensor 11. Both the first sensor 4 and the second sensor 11 are connected to the upper computer 7, and the upper computer 7 passes the first sensor 4 and the second sensor. The vibration frequency collected by the sensor 11 monitors the vibration frequency of the powder mixing container 3; the host computer 7 controls the acceleration of the vibration table body 2 at the same time, and the host computer 7 controls the vibration frequency and acceleration of the vibration table body 2 through a vibration controller.

The power supply 5 is connected to the vibrating table body 2 and the cooling fan 1 at the same time, and then supplies power to the two devices at the same time. The cooling fan 1 is connected to the vibrating table body 1. The cooling fan 1 is used to cool the electric current and the motor in the vibrating table body 2. Heat generated during exercise.

The principle of the industrial-grade vibrating table of the present invention usually provides large thrust with electromagnetic control, and the selection range of vibration parameters is very wide, such as the excitation force can be from small 1960N (moving coil weight 2Kg) to large 156800N (moving coil weight 160kg). Under the acceleration of 60G (G is the acceleration of gravity), the powder mixing weight of the small vibration table is 1960/(60×9.8)-2=1.3Kg each time, and the powder mixing weight of the small vibration table is 156800/(60×9.8) )-160=107Kg. It can be seen that the electromagnetically controlled vibrating table combined with the device designed by the present invention can efficiently mix powder on a large scale.

The process of mixing powder by the above-mentioned device comprises the following steps:

1. Place the powder to be mixed inside the powder mixing container 3, place the powder mixing container 3 on the vibrating table body 2, and fix the powder mixing container 3 on the vibrating table body 2, more specifically, put The screw holes of the bottom plate 10 are aligned with the nut holes on the top of the vibrating table body 2, cover the cover plate 9, pass 8 bolts through the coaxial screw holes of the cover plate 9 and the bottom plate 10, and screw them into the screw holes of the vibrating table body 2. Among the nuts, tighten the screws to completely fix the cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Open all two quick plugs 8, turn on the switch at the argon decompression valve, adjust the flow rate of argon gas, connect the argon gas pipeline to one quick plug 8 when the flow rate is 10-30cm ³ /min, and mix the powder Wash the inside of the container 8 for 1-3 minutes, pull out the argon gas pipeline, and close the two quick plugs 8 in time.

3. Fix the first sensor 4 to the lower cover plate of the powder mixing container 3 for monitoring the vibration frequency during the powder mixing process. The second sensor 11 is fixed on the vibrating table body 2 for monitoring and controlling parameters in the powder mixing process. The two sensors simultaneously monitor the vibration frequencies of the two devices to prevent the vibration frequency of the vibrating table body 2 from being fully transmitted to the powder mixing container 3, which affects the powder mixing effect.

4. Set the vibration frequency range of the vibrating table body 1 to f _min - f _max through the host computer 7, set the first acceleration and compression factor, and start mixing powder;

5. Determine the optimal vibration frequency. The vibration frequency of the vibrating table body 1 begins to vibrate from f _min , and the vibration frequency begins to increase with the set acceleration value until it increases to f _max . Observe the vibration degree of the powder. When the powder vibrates When the degree is the most severe, record the corresponding frequency, which is the optimal frequency value f _best . During the vibration process, if the powder vibration is found to be relatively gentle, you can consider adjusting the starting point frequency, the ending point frequency, and the acceleration value, and re-select the optimal frequency value.

6. During the powder mixing process, set the vibration range f ₁ -f ₂ or f _best through the host computer again, f _min <f ₁ <f _best , f _best <f ₂ <f _max , dwell time and second acceleration value, Make the vibrating table body vibrate between f ₁ and f ₂ ; the vibration frequency of the vibrating table body 1 starts to vibrate from f ₁ , continuously accelerates with the second acceleration value during the vibration process, and then continues to rise to f _max , vibrating end; or vibrate at f _best frequency for a certain period of time.

7. After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices for sealed storage, and use it for subsequent additive manufacturing.

The mixed powder prepared by the above preparation method includes a composite main powder and an additional powder, the additional powder is dispersed on the surface of the main powder, or a part of the additional powder is infiltrated into the main powder; the main powder is aluminum alloy, titanium alloy, high-entropy alloy, steel or superalloy; the additional powder is metal powder, carbide, boride or nitride; the main powder is micron-scale, and the additional powder is micron-scale or nano-scale.

Next step is further described in conjunction with specific embodiment:

Example 1

1. Installation: first pour a certain amount of WC into the powder mixing container 3, then pour about 1Kg of CoCrFeNi high-entropy alloy powder into the powder mixing container 3, cover the WC powder to prevent the WC from being blown away, and put the mixing The powder container 3 is placed above the vibrating table body 2. It is required to align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, and pass 8 bolts through the 2 Al alloy covers. The screw holes of the plate 9 are screwed into the nuts of the vibrating table body 2, and the screws are tightened to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm ³ /min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for 3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 40 and 200Hz respectively, that is, f _min is 40 and f _max is 200Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 40Hz, and the end point frequency is defined as 200Hz. Enter a frequency of 40 and 200Hz at the start point and end point of the default compression factor 1 column, respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 100 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 100Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 2. The WC powder is evenly distributed on the powder surface. The white WC powder is relatively fine, but it can be found that there is no agglomeration phenomenon. The distribution on the surface of the CoCrFeNi high-entropy alloy powder is very uniform, which can be used for additive manufacture.

Example 2

1. Installation: first pour a certain quality of TiC into the powder mixing container 3, then pour about 1Kg of CoCrFeNi high-entropy alloy powder into the powder mixing container 3, cover the TiC powder to prevent the TiC from being blown away, and put the The powder container 3 is placed above the vibrating table body 2. It is required to align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, and pass 8 bolts through the 2 Al alloy covers. The screw holes of the plate 9 are screwed into the nuts of the vibrating table body 2, and the screws are tightened to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm3/min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for 1 minute, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 40 and 200Hz respectively, that is, f _min is 40 and f _max is 200Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 40Hz, and the end point frequency is defined as 200Hz. Enter a frequency of 40 and 200Hz at the start point and end point of the default compression factor 1 column, respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 90 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 90Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 3. The granular white TiB powder is evenly distributed on the surface of the CoCrFeNi high-entropy alloy powder and the TiB powder does not agglomerate. Due to its good dispersion, it can be used for additive manufacturing.

Example 3

1. Installation: First, pour a certain amount of Y ₂ O ₃ into the powder mixing container 3, then pour about 1Kg of CoCrFeNi high-entropy alloy powder into the powder mixing container 3, and cover the Y ₂ O ₃ powder to prevent Y2O3 blown away, place the powder mixing container 3 on the top of the vibrating table body 2, align the screw holes of the bottom plate 10 with the nut holes on the top of the vibrating table body 2, cover the Al alloy cover plate 9, and put 8 bolts through Through the screw holes of the two Al alloy cover plates 9, screw them into the nuts of the vibrating table body 2, tighten the screws, and completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm3/min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for 2 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 40 and 200Hz respectively, that is, f _min is 40 and f _max is 200Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 40Hz, and the end point frequency is defined as 200Hz. Enter a frequency of 40 and 200Hz at the start point and end point of the default compression factor 1 column, respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 70 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 70Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 4. The fine Y ₂ O ₃ powder is evenly distributed on the powder surface. Due to the relatively small amount of addition, the Y ₂ O ₃ powder does not completely cover the surface of the CoCrFeNi high-entropy alloy powder, but its distribution is very uniform.

Example 4

1. Installation: first pour a certain quality of Y ₂ O ₃ into the powder mixing container 3, then pour about 1Kg of IN625 superalloy powder into the powder mixing container 3, and cover the oxide powder to prevent Y ₂ O ₃ The metal powder is blown away, and the powder mixing container 3 is placed on the top of the vibrating table body 2. It is required to align the screw holes of the bottom plate 10 with the nut holes on the top of the vibrating table body 2, cover the Al alloy cover plate 9, and put 8 Bolts pass through the screw holes of the two Al alloy cover plates 9, are screwed into the nuts of the vibrating table body 2, and the screws are tightened to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm ³ /min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for 3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 40 and 200Hz respectively, that is, f _min is 40 and f _max is 200Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 40Hz, and the end point frequency is defined as 200Hz. Enter a frequency of 40 and 200Hz at the start point and end point of the default compression factor 1 column, respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 88 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 80Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 5. The Y ₂ O ₃ powder is evenly distributed on the powder surface and the Y ₂ O ₃ powder almost completely covers the entire IN625 superalloy powder, forming a thin layer on the surface of the IN625 superalloy powder. Y ₂ O ₃ powder layer, which realizes uniform mixing of Y ₂ O ₃ powder, can be used for additive manufacturing.

Example 5

1. Installation: first pour a certain amount of B into the powder mixing container 3, then pour about 1Kg of Ti55531 titanium alloy powder into the powder mixing container 3, cover the B powder to prevent the B powder from being blown away, and put the The powder container 3 is placed above the vibrating table body 2. It is required to align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, and pass 8 bolts through the 2 Al alloy covers. The screw holes of the plate 9 are screwed into the nuts of the vibrating table body 2, and the screws are tightened to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm ³ /min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for about 1-3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 15 and 100Hz respectively, that is, f _min is 15 and f _max is 100Hz, and the acceleration is defined as 15g. In the default sweep frequency 1 column, the start point frequency is defined as 15Hz, and the end point frequency is defined as 100Hz. Enter frequency 15 and 100Hz at the start point and end point of the default compression factor 1 column respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, and there is no optimal frequency in this embodiment, but an optimal frequency range (20-30 Hz). If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: According to the basic settings in step 1, select 20Hz and 30Hz, that is, f ₁ is 20Hz, and f ₂ is 30Hz; they are used as the start point frequency and end point frequency respectively. Repeat step 1 for the basic setup. Add the "resident" type to column 1 of the plan table,. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 6(b). The micron-sized B powder is attached to the surface of the Ti55531 titanium alloy powder, and the smaller B powder becomes the planetary powder of the larger Ti55531 titanium alloy powder. From the overall effect diagram (a) It can be observed that the distribution of B powder on the surface of Ti55531 titanium alloy powder is relatively uniform, which can be used for additive manufacturing.

Example 6

1. Installation: first pour 1Kg of AlSi10Mg alloy powder into the powder mixing container 3, then pour a certain amount of TiB ₂ into the powder mixing container 3, and place the powder mixing container 3 on the top of the vibrating table body 2. Align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, pass 8 bolts through the screw holes of the two Al alloy cover plates 9, and screw them into the vibrating table body 2 Among the nuts, tighten the screws to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm3/min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for about 3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 0 and 50Hz respectively, that is, f _min is 0 and f _max is 50Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 0Hz, and the end point frequency is defined as 50Hz. Enter frequency 0 and 50Hz at the start point and end point of the default compression factor 1 column respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, and there is no optimal frequency in this embodiment, but an optimal frequency range (10-25 Hz). If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: According to the basic settings in step 1, select 10Hz and 25Hz, that is, f ₁ is 10Hz, and f ₂ is 25Hz; they are used as the start point frequency and end point frequency respectively. Repeat step 1 for the basic setup. Add "Residence" type in Schedule 1 column. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use. The mixed powder is shown in Figure 7. The nanoscale white TiB ₂ powder is evenly distributed on the surface of the AlSi10Mg alloy powder and the TiB ₂ powder does not agglomerate. It has good dispersion on the surface of the AlSi10Mg alloy powder and can be used for additive manufacturing. .

Example 7

1. Installation: first pour 1Kg of 316L stainless steel alloy powder into the powder mixing container 3, then pour a certain mass of Ti ₃ N ₄ into the powder mixing container 3, and place the powder mixing container 3 on the vibrating table body 2 Above, it is required to align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, pass 8 bolts through the screw holes of the two Al alloy cover plates 9, and screw them into the vibrating table Among the nuts of the table body 2, tighten the screws to completely fix the upper cover plate 9, the powder mixing container 3 and the vibration table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm3/min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for about 3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequencies in the frequency column of sweep spectrum 1, which are 0 and 40Hz respectively, that is, f _min is 0 and f _max is 40Hz, and the acceleration is defined as 35g. In the default sweep frequency 1 column, the start point frequency is defined as 0Hz, and the end point frequency is defined as 40Hz. Enter frequency 0 and 40Hz at the start point and end point of the default compression factor 1 column respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 9 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 9Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use.

Example 7

1. Installation: first pour a certain amount of metal Mo powder into the powder mixing container 3, and then pour about 1Kg of pure Ti powder into the powder mixing container 3 to cover the metal Mo powder to prevent the metal Mo from being blown away. Place the powder mixing container 3 above the vibrating table body 2. It is required to align the screw holes of the bottom plate 10 with the nut holes above the vibrating table body 2, cover the Al alloy cover plate 9, and pass 8 bolts through 2 Al alloy The screw holes of the alloy cover plate 9 are screwed into the nuts of the vibrating table body 2, and the screws are tightened to completely fix the upper cover plate 9, the powder mixing container 3 and the vibrating table body 2 together.

2. Air washing: Open all the two quick plugs 8. Turn on the switch at the argon decompression valve of the argon source 6, adjust the flow rate of the argon gas, and when the flow rate is 10-30 cm ³ /min, connect the argon gas pipeline to the quick plug 8 for gas washing. After purging for about 1-3 minutes, pull out the argon gas pipeline, and close the two quick plugs in time.

3. Paste the sensor: Paste the first sensor 4 on the bottom plate 10 of the powder mixing container 3 for monitoring the parameters in the powder mixing process. Paste the second sensor on the vibrating table body 2 to control the parameters in the powder mixing process.

4. Basic settings: Open the operating software and click to write the test plan. Add two rows of frequency to the frequency column of sweep spectrum 1, which are 15 and 80Hz respectively, that is, f _min is 15 and f _max is 80Hz, and the acceleration is defined as 15g. In the default sweep frequency 1 column, the start point frequency is defined as 15Hz, and the end point frequency is defined as 80Hz. Enter a frequency of 15 and 80Hz at the start point and end point of the default compression factor 1 column, respectively, and the default compression factor is 5. After the setting is completed, click the start button to start the powder mixing process.

5. Find the optimal parameters: pay attention to the vibration of the powder inside the powder mixing container with the naked eye, and record the corresponding frequency when the powder vibrates up and down most violently (the vibrated powder touches the upper cover). This frequency is an optimal frequency value, which is 25 Hz in this embodiment. If it is found that the powder vibration is relatively gentle, you can consider adjusting the start point frequency, end point frequency, and acceleration value, and re-select the optimal frequency value.

6. Powder mixing process: Repeat step 1 for basic settings. Add the "dwell" type in column 1 of the plan table, and define the start frequency as 15Hz, which is the optimal frequency value. Set the dwell time in the time column and set it to 3 minutes. Then click the Start button. After 3 minutes, the first powder mixing process is over, and stay for 1 minute to let the container dissipate heat. Then repeat this powder mixing process 3 times for a total of 12 minutes of mixing. Complete the mixing process. It can be considered to perform the air washing process again after mixing the powder twice to ensure the internal atmosphere of the powder mixing container.

7. Disassembly: After the powder mixing is completed, first remove the two sensors, then unscrew the bolts, remove the upper cover, dry the mixed powder, pour it into other storage devices and store it sealed for subsequent additive manufacturing use.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (3)

1. A method of preparing a mixed powder for additive manufacturing, comprising the steps of:

step 1, placing main powder and additional powder together in a powder mixing container (3) to form mixed powder, and placing the powder mixing container (3) on a vibrating table body (2);

the main powder is aluminum alloy, titanium alloy, high-entropy alloy, steel or high-temperature alloy;

the additional powder is metal powder, non-metal simple substance powder, carbide, boride or nitride;

the main powder and the additional powder are compounded through mixing vibration; the additional powder is dispersed on the surface of the main powder, or a part of the additional powder is permeated into the main powder;

the main powder is in a micron level, and the additional powder is in a micron level or a nanometer level;

step 2, washing the inside of the powder mixing container (3);

step 3, setting the vibration frequency range of the vibration table body (2) as f _min ~f _max Setting a first acceleration value and a compression factor; the vibrating table body (2) is from f under the first acceleration _min Starting to vibrate, and gradually increasing the vibration frequency to f _max The method comprises the steps of carrying out a first treatment on the surface of the Observing the vibration degree of the mixed powder in the process, and recording a corresponding frequency fixed value or a frequency interval when the vibration degree of the mixed powder is the strongest; the frequency of the mixed powder when the oscillation degree is most intense is the optimal frequency f _best Or an optimal frequency interval (f ₁ ，f ₂ ) The method comprises the steps of carrying out a first treatment on the surface of the If the oscillation of the powder is always gentle, f is reset _min And f _max Repeating the above process until finding the optimal frequency f _best Or an optimal frequency interval (f ₁ ，f ₂ ）；

Step 4, resetting the second acceleration value and the vibration residence time of the vibration table body (2), if the mixed powder has the optimal frequency f _best Setting residence time, vibrating table body (2) at f _best Vibrating at the frequency until the set residence time is reached, and ending the vibration; if there is an optimal frequency interval (f ₁ ，f ₂ ) Under the second acceleration, the vibrating table body (2) vibrates from f ₁ Starting to vibrate, gradually increasing the vibration frequency to f according to the set residence time ₂ Ending the vibration;

f ₁ =f _best -（5~40）Hz，f ₂ =f _best +（10~40）Hz；

the powder mixing process is repeated for a plurality of times; a heat dissipation process and a gas washing process are arranged between the two powder mixing processes;

and 5, taking out the mixed powder after the powder mixing is finished for later use.

2. The method of mixing additive manufacturing powder according to claim 1, wherein in step 1, the powder mixing container (3) and the vibrating table body (2) are fixedly connected.

3. The method of mixing additive manufacturing powder according to claim 1, wherein in step 2, the powder mixing container (3) is purged with argon for 1-3min at a purge flow rate of 10-30 cm ³ /min。

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