CN105522161A - Rapid large-scale preparing method for small-grain-size spherical powder for 3D printing - Google Patents

Abstract

The invention relates to a rapid large-scale preparation method of fine-grained spherical powder for 3D printing, and belongs to the technical field of preparation of spherical powder materials. The method includes the following steps: Step 1: Obtain powder in the required particle size range or use a vibrating sieve to sieve existing powder to obtain powder in the required particle size range; Step 2: Adjust parameters to obtain a stable plasma; Step 3: Use continuous feeding The powder device sends the powder in step 1 into the plasma; step 4: use high-temperature plasma to melt the powder, and the molten droplet forms a ball under the action of surface tension, and the spherical droplet cools and falls rapidly under the action of dispersed gas and gravity, Finally, the spherical fine particle size powder for 3D printing is obtained in the collector. The method can quickly and large-scale produce fine particle size powder with good fluidity, low impurity content, high spheroidization rate, good sphericity and high yield, which meets the requirements of 3D printing and spraying industries.

Description

A rapid and large-scale preparation method of fine-grained spherical powder for 3D printing

technical field

The invention belongs to the technical field of preparation of spherical powder materials, and relates to a rapid large-scale preparation method of fine-grained spherical powder for 3D printing.

Background technique

3D printing technology, also known as additive manufacturing technology, is a green and intelligent manufacturing technology, known as one of the carriers of the "third industrial revolution". Compared with the traditional processing methods of material reduction and equal material, 3D printing technology has the advantages of fast flexibility, material saving, and personalized customization. It has obvious advantages in the processing of parts with high melting point and complex shapes of traditional difficult-to-process materials. At present, high-performance materials are one of the key factors restricting the development and application of 3D printing technology, which determines the performance and accuracy of the final printed parts.

At present, the preparation methods of powder materials for 3D printing mainly include atomization method, plasma rotating electrode method and other methods. These methods mainly use rods or wires as raw materials, melt the materials at high temperatures, and then blow off the liquid by centrifugal force or gas to obtain spherical powders. These methods are due to the limitations of their own conditions, the particle size of the obtained spherical powder is too large, the particle size distribution is not uniform, and the yield of fine-grained powder is low. Therefore, it is very important to provide a method for efficiently producing spherical fine-grained 3D printing powders.

Plasma spheroidization technology uses high-temperature plasma to melt powder, and the molten powder forms a spherical shape under the action of surface tension, and the spherical droplet cools and falls under the action of gravity and dispersed gas, and finally obtains spherical powder in the collector.

Contents of the invention

In view of this, the purpose of the present invention is to provide a rapid large-scale preparation method for fine-grained spherical powder for 3D printing, which can be rapidly and large-scale produced And fine-grained powder with high yield, which meets the requirements of 3D printing and spraying industries.

To achieve the above object, the present invention provides the following technical solutions:

A method for rapid large-scale preparation of fine-grained spherical powder for 3D printing, comprising the following steps:

Step 1: Obtain the powder in the required particle size range or use a vibrating sieve to sieve the existing powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: using a continuous powder feeding device to send the powder in step 1 into the plasma;

Step 4: Use high-temperature plasma to melt the powder, and the molten droplets form balls under the action of surface tension, and the spherical droplets cool down and fall rapidly under the action of dispersed gas and gravity, and finally obtain spherical particles for 3D printing in the collector. particle size powder.

Further, the powders mentioned in step 1 include but are not limited to tungsten powder, stainless steel powder, nickel-based alloy powder, die steel powder, titanium alloy powder, magnesium oxide and other powders.

Further, the vibrating sieve in the step 1 is 150 mesh, or the raw powder of less than 150 mesh is obtained.

Further, the conditions for stable plasma operation in step 2 are that the total flow rate of plasma gas is 50-100 slpm, the plasma power is 20-50 kW, the flow rate of protective gas is 0-50 slpm, and the pressure inside the reactor is 7-16 psia.

Further, the powder feeding device in step 3 is a continuous powder feeding device, the bottom of the device is a vibrating powder feeder connected to the controller, and the top of the device is a transition chamber that can be continuously filled and vacuumed without affecting the plasma powder spheroidization process .

Further, in step 4, the total flow rate of the carrier gas and the dispersing gas is 1-30 slpm, the distance between the powder outflow position and the plasma center is 0-50 mm, and the powder flow rate is 0.5-9 Kg/h.

The beneficial effect of the present invention is that: the rapid large-scale preparation method of a fine-grained spherical powder for 3D printing according to the present invention, first obtain the fine-grained powder whose composition and particle size meet the requirements or sieve the existing powder , to obtain the powder with the required particle size; then adjust the parameters to establish a stable plasma; use the continuous powder feeder to send the powder into the plasma under the action of the carrier gas; adjust the parameters such as the flow rate of the carrier gas and dispersion gas to obtain the nodularization High, fine-grained powder with good sphericity, good fluidity and high yield. Compared with the preparation methods of other spherical powder materials, the method has the advantages of less impurity content, high yield of fine powder and the like.

Description of drawings

In order to make the purpose, technical scheme and beneficial effect of the present invention clearer, the present invention provides the following drawings for illustration:

Fig. 1 is a schematic flow sheet of the method of the present invention;

Fig. 2 is the topography figure of embodiment 1 gained spherical powder;

Fig. 3 is the topography figure of embodiment 2 gained spherical powder;

Fig. 4 is the topography figure of embodiment 3 gained spherical powder;

Fig. 5 is the topography figure of embodiment 4 gained spherical powder;

Fig. 6 is the morphology figure of the spherical powder obtained in Example 5.

detailed description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Figure 1 is a schematic flow chart of the method of the present invention, as shown in the figure, the method includes the following steps: Step 1: Obtain powder in the required particle size range or use a vibrating sieve to sieve existing powder to obtain powder in the required particle size range; Step 2: Adjust the parameters to obtain a stable plasma; Step 3: Use a continuous powder feeding device to send the powder in Step 1 into the plasma; Step 4: Use high-temperature plasma to melt the powder, and the molten droplets are under the action of surface tension Balls are formed, and the spherical droplets are rapidly cooled and fallen under the action of dispersed gas and gravity, and finally the spherical fine-grained powder for 3D printing is obtained in the collector.

Example 1:

In this embodiment, a rapid large-scale preparation method of fine-grained spherical powder for 3D printing includes the following steps:

Step 1: Purchase the powder in the required particle size range or use a vibrating sieve to sieve the purchased powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: Use the continuous powder feeding device to convey the powder;

Step 4: Use high-temperature plasma to melt the powder, and adjust the parameters to obtain a powder with high spheroidization rate and high yield.

Wherein, the particle size of the stainless steel powder purchased in step 1 is less than 100um; The operating parameters of stable plasma in step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of shielding gas is 3slpm, and the pressure in the reactor is 15 psia; the vibration frequency of the vibratory powder feeder used in step 3 was 120 and the amplitude was 55. The transition chamber at the top of the continuous powder feeding device can be continuously filled and vacuumed without affecting the plasma powder spheroidization process. In step 4, the total flow rate of the carrier gas and the dispersion gas is 10 slpm, the distance between the powder outflow position and the plasma center position is 20 mm, and the powder flow rate is 3.5 Kg/h. Fig. 2 is the morphology figure of the spherical powder obtained in embodiment 1.

Example 2:

A method for rapid large-scale preparation of fine-grained spherical powder for 3D printing in this embodiment comprises the following steps:

Step 1: Purchase the powder in the required particle size range or use a vibrating sieve to sieve the purchased powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: Use the continuous powder feeding device to convey the powder;

Step 4: Use high-temperature plasma to melt the powder, and adjust the parameters to obtain a powder with high spheroidization rate.

Among them, in this embodiment:

In step 1, the purchased tungsten powder is sieved to obtain a powder with a particle size less than 100um;

The operating parameters of the stable plasma in step 2 are that the total flow rate of the plasma gas is 70 slpm, the plasma power is 40 kW, the flow rate of the protective gas is 3 slpm, and the pressure in the reactor is 15 psia;

The vibratory powder feeder used in step 3 has a vibration frequency of 115 and an amplitude of 20. The transition chamber at the top of the continuous powder feeding device can be continuously filled and vacuumed without affecting the plasma powder spheroidization process.

In step 4, the total flow rate of the carrier gas and the dispersion gas is 10 slpm, the distance between the powder outflow position and the plasma center position is 5 mm, and the powder flow rate is 1.5 Kg/h. Fig. 3 is the morphology figure of the spherical powder obtained in Example 2.

Example 3:

In this embodiment, a rapid large-scale preparation method of fine-grained spherical powder for 3D printing comprises the following steps:

Step 1: Purchase the powder in the required particle size range or use a vibrating sieve to sieve the purchased powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: Use the continuous powder feeding device to convey the powder;

Step 4: Use high-temperature plasma to melt the powder, and adjust the parameters to obtain a powder with high spheroidization rate.

Wherein, in this embodiment: the particle size of the titanium alloy powder purchased in step 1 is less than 100um; the operating parameters of the stable plasma in step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, and the flow rate of shielding gas is 35slpm. The pressure in the reactor is 15 psia; the vibration frequency of the vibratory powder feeder used in step 3 is 125, and the amplitude is 60. The transition chamber at the top of the continuous powder feeding device can be continuously filled and vacuumed without affecting the plasma powder spheroidization process. In step 4, the total flow rate of the carrier gas and the dispersion gas is 10 slpm, the distance between the powder outflow position and the plasma center position is 20 mm, and the powder flow rate is 2.6 Kg/h. Fig. 4 is the morphology figure of the spherical powder obtained in embodiment 3.

Example 4:

In this embodiment, a rapid large-scale preparation method of fine-grained spherical powder for 3D printing comprises the following steps:

Step 1: Purchase the powder in the required particle size range or use a vibrating sieve to sieve the purchased powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: Use the continuous powder feeding device to convey the powder;

Step 4: Use high-temperature plasma to melt the powder, and adjust the parameters to obtain a powder with high spheroidization rate and high yield.

Wherein, in this embodiment: the particle size of the nickel-based alloy powder purchased in step 1 is less than 100um; the operating parameters of the stable plasma in step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, and the flow rate of shielding gas is 3slpm , the pressure in the reactor is 15 psia; the vibration frequency of the vibratory powder feeder used in step 3 is 115, and the amplitude is 40. The transition chamber at the top of the continuous powder feeding device can be continuously filled and vacuumed without affecting the plasma powder spheroidization process. In step 4, the total flow rate of the carrier gas and the dispersion gas is 10 slpm, the distance between the powder outflow position and the plasma center position is 20 mm, and the powder flow rate is 2.6 Kg/h. Fig. 5 is the topography diagram of the spherical powder obtained in Example 4.

Example 5:

In this embodiment, a rapid large-scale preparation method of fine-grained spherical powder for 3D printing comprises the following steps:

Step 1: Purchase the powder in the required particle size range or use a vibrating sieve to sieve the purchased powder to obtain the powder in the required particle size range;

Step 2: adjust the parameters to obtain a stable plasma;

Step 3: Use the continuous powder feeding device to convey the powder;

Step 4: Use high-temperature plasma to melt the powder, and adjust the parameters to obtain a powder with high spheroidization rate.

Wherein, in this embodiment: the particle size of the mold steel powder purchased in step 1 is less than 100um; the operating parameters of the stable plasma in step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, and the flow rate of shielding gas is 3slpm, The pressure in the reactor is 15 psia; the vibration frequency of the vibratory powder feeder used in step 3 is 125, and the amplitude is 55. The transition chamber at the top of the continuous powder feeding device can be continuously filled and vacuumed without affecting the plasma powder spheroidization process. In step 4, the total flow rate of the carrier gas and the dispersion gas is 10 slpm, the distance between the powder outflow position and the plasma center position is 20 mm, and the powder flow rate is 3 Kg/h.

It should be noted that, in the preferred method of rapid large-scale preparation of fine-grained spherical powder for 3D printing in the present invention, the purchased powder in step 1 is less than 150 mesh, or the purchased powder is sieved through a 150-mesh vibrating sieve; The parameters for plasma stable operation in step 2 are that the total flow rate of plasma gas is 50-100 slpm, the plasma power is 20-50 kW, the flow rate of protective gas is 0-50 slpm, and the pressure in the reactor is 7-16 psia; the vibration used in step 3 The vibration frequency of the powder feeder is 90-150, and the amplitude is 30-80; the total flow rate of the carrier gas and dispersion gas in step 4 is 1-20 slpm, the distance between the powder outflow position and the plasma center position is 0-50 mm, and the powder flow rate is 0.5 When ~9Kg/h all can realize the object of the present invention.

Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that it can be described in terms of form and Various changes may be made in the details without departing from the scope of the invention defined by the claims.

Claims (6)

1. a kind of rapid large-scale preparation method of fine-grained spherical powder for 3D printing, it is characterized in that: comprise the following steps: Step 1: Obtain the powder in the required particle size range or use a vibrating sieve to sieve the existing powder to obtain the powder in the required particle size range; Step 2: adjust the parameters to obtain a stable plasma; Step 3: using a continuous powder feeding device to send the powder in step 1 into the plasma; Step 4: Use high-temperature plasma to melt the powder, and the molten droplets form balls under the action of surface tension, and the spherical droplets cool down and fall rapidly under the action of dispersed gas and gravity, and finally obtain spherical particles for 3D printing in the collector. particle size powder. 2. The rapid large-scale preparation method of fine-grained spherical powder for 3D printing according to claim 1, characterized in that: the powder described in step 1 includes but not limited to tungsten powder, stainless steel powder, nickel-based alloy powder, mold steel powder, titanium alloy powder, magnesium oxide and other powders. 3. The rapid large-scale preparation method of fine-grained spherical powder for 3D printing according to claim 1, characterized in that: the vibrating sieve in the step 1 is 150 mesh, or the original powder of less than 150 mesh is obtained. 4. The rapid large-scale preparation method of a fine-grained spherical powder for 3D printing according to claim 1, characterized in that: the condition for the stable operation of the plasma in step 2 is that the total flow rate of the plasma gas is 50-100 slpm, The plasma power is 20-50kW, the protective gas flow rate is 0-50slpm, and the pressure inside the reactor is 7-16psia. 5. A rapid large-scale preparation method for fine-grained spherical powder for 3D printing according to claim 1, characterized in that: the powder feeding device in step 3 is a continuous powder feeding device, and the bottom of the device is connected to the controller The vibrating powder feeder is connected, and the top of the device is a transition chamber that can be continuously filled and vacuumed without affecting the plasma powder spheroidization process. 6. A rapid large-scale preparation method for fine-grained spherical powders for 3D printing according to claim 1, characterized in that: in step 4, the total flow rate of the carrier gas and the dispersion gas is 1-30 slpm, and the powder outflow position and the plasma The distance between the body centers is 0-50mm, and the powder flow rate is 0.5-9Kg/h.