Disclosure of Invention
In view of the above, the invention aims to provide a rapid large-scale preparation method of a fine-particle-size spherical powder for 3D printing, which can rapidly produce the fine-particle-size powder with good flowability, low impurity content, high spheroidization rate, good sphericity and high yield on a large scale, and meet the requirements of industries such as 3D printing and spraying.
In order to achieve the purpose, the invention provides the following technical scheme:
a rapid large-scale preparation method of fine-particle-size spherical powder for 3D printing comprises the following steps:
step 1: obtaining powder in a required particle size range or screening the existing powder by using a vibrating screen to obtain powder in the required particle size range, wherein the powder comprises but is not limited to tungsten powder, stainless steel powder, nickel-based alloy powder, die steel powder, titanium alloy powder, magnesium oxide powder and the like;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: the powder in the step 1 is fed into plasma by using a continuous powder feeding device, the bottom of the device is provided with a vibrating powder feeder connected with a controller, and the top of the device is provided with a transition bin which can be continuously filled and vacuumized without influencing the spheroidization process of the plasma powder;
and 4, step 4: the powder is melted by high-temperature plasma, the melted liquid drops form spheres under the action of surface tension, the spherical liquid drops are rapidly cooled and fall under the action of dispersing gas and gravity, and finally the spherical fine-grain-size powder for 3D printing is obtained in a collector.
Further, the powder described in step 1 includes, but is not limited to, tungsten powder, stainless steel powder, nickel-based alloy powder, die steel powder, titanium alloy powder, magnesium oxide powder, and the like.
Further, the vibrating screen in the step 1 is 150 meshes, or raw powder with the size less than 150 meshes is obtained.
Further, the stable operation conditions of the plasma in the step 2 are that the total flow rate of the plasma gas is 50-100 slpm, the plasma power is 20-50 kW, the flow rate of the protective gas is 0-50 slpm, and the pressure in the reactor is 7-16 psia.
Further, in the 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 position is 0-50 mm, and the powder flow is 0.5-9 Kg/h.
The invention has the beneficial effects that: the invention relates to a rapid large-scale preparation method of fine-particle-size spherical powder for 3D printing, which comprises the steps of firstly obtaining fine-particle powder with components and particle sizes meeting requirements or screening the existing powder to obtain powder with required particle sizes; then adjusting parameters and establishing stable plasma; feeding the powder into the plasma under the action of carrier gas by using a continuous powder feeder; and adjusting parameters such as flow of carrier gas and dispersing gas to obtain fine-grained powder with high spheroidization rate, good sphericity, good fluidity and high yield. Compared with other preparation methods of spherical powder materials, the method has the advantages of low impurity content, high fine powder yield and the like.
Detailed Description
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Fig. 1 is a schematic flow chart of the method of the present invention, and as shown in the figure, the method includes the steps of: step 1: obtaining powder with a required particle size range or screening existing powder by using a vibrating screen to obtain powder with the required particle size range; step 2: adjusting parameters to obtain stably running plasma; and step 3: feeding the powder in the step 1 into plasma by using a continuous powder feeding device;
and 4, step 4: the powder is melted by high-temperature plasma, the melted liquid drops form spheres under the action of surface tension, the spherical liquid drops are rapidly cooled and fall under the action of dispersing gas and gravity, and finally the spherical fine-grain-size powder for 3D printing is obtained in a collector.
Example 1:
in this embodiment, a method for rapidly preparing a spherical powder with a fine particle size for 3D printing in a large scale includes the following steps:
step 1: purchasing powder in a required particle size range or screening the purchased powder by using a vibrating screen to obtain powder in the required particle size range;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: conveying the powder by using a continuous powder feeding device;
and 4, step 4: the powder is melted by high-temperature plasma, and the powder with high spheroidization rate and high yield is obtained by adjusting parameters.
Wherein the granularity of the stainless steel powder purchased in the step 1 is less than 100 um; the operation parameters of stabilizing the plasma in the step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of protective gas is 3slpm, and the pressure in the reactor is 15 psia; the vibration frequency of the vibration powder feeder used in step 3 was 120, and the amplitude was 55. The transition bin at the top of the continuous powder feeding device can be used for continuously filling and vacuumizing without influencing the plasma powder spheroidizing process. In the step 4, the total flow of the carrier gas and the dispersion gas is 10slpm, the distance between the powder outflow position and the plasma center position is 20mm, and the powder flow is 3.5 Kg/h. FIG. 2 is a graph showing the morphology of the spherical powder obtained in example 1.
Example 2:
the rapid large-scale preparation method of the fine-particle-size spherical powder for 3D printing in the embodiment comprises the following steps:
step 1: purchasing powder in a required particle size range or screening the purchased powder by using a vibrating screen to obtain powder in the required particle size range;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: conveying the powder by using a continuous powder feeding device;
and 4, step 4: and melting the powder by using high-temperature plasma, and adjusting parameters to obtain the powder with high spheroidization rate.
Among them, in this embodiment:
sieving the purchased tungsten powder in the step 1 to obtain powder with the granularity less than 100 um;
the operation parameters of stabilizing the plasma in the step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of protective gas is 3slpm, and the pressure in the reactor is 15 psia;
the vibration frequency of the vibration powder feeder used in step 3 was 115, and the amplitude was 20. The transition bin at the top of the continuous powder feeding device can be used for continuously filling and vacuumizing without influencing the plasma powder spheroidizing process.
In the step 4, the total flow of the carrier gas and the dispersion gas is 10slpm, the distance between the powder outflow position and the plasma center position is 5mm, and the powder flow is 1.5 Kg/h. FIG. 3 is a graph showing the morphology of the spherical powder obtained in example 2.
Example 3:
the embodiment of the invention provides a rapid large-scale preparation method of fine-particle-size spherical powder for 3D printing, which comprises the following steps:
step 1: purchasing powder in a required particle size range or screening the purchased powder by using a vibrating screen to obtain powder in the required particle size range;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: conveying the powder by using a continuous powder feeding device;
and 4, step 4: and melting the powder by using high-temperature plasma, and adjusting parameters to obtain the powder with high spheroidization rate.
Among them, in this embodiment: the granularity of the titanium alloy powder purchased in the step 1 is less than 100 um; the operation parameters of stabilizing the plasma in the step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of protective gas is 35slpm, and the pressure in the reactor is 15 psia; the vibration frequency of the vibration powder feeder used in step 3 was 125, and the amplitude was 60. The transition bin at the top of the continuous powder feeding device can be used for continuously filling and vacuumizing without influencing the plasma powder spheroidizing process. In the step 4, the total flow of the carrier gas and the dispersion gas is 10slpm, the distance between the powder outflow position and the plasma center position is 20mm, and the powder flow is 2.6 Kg/h. FIG. 4 is a graph showing the morphology of the spherical powder obtained in example 3.
Example 4:
the embodiment of the invention provides a rapid large-scale preparation method of fine-particle-size spherical powder for 3D printing, which comprises the following steps:
step 1: purchasing powder in a required particle size range or screening the purchased powder by using a vibrating screen to obtain powder in the required particle size range;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: conveying the powder by using a continuous powder feeding device;
and 4, step 4: and melting the powder by using high-temperature plasma, and adjusting parameters to obtain the powder with high spheroidization rate and yield.
Among them, in this embodiment: the granularity of the nickel-based alloy powder purchased in the step 1 is less than 100 um; the operation parameters of stabilizing the plasma in the step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of protective gas is 3slpm, and the pressure in the reactor is 15 psia; the vibration frequency of the vibration powder feeder used in step 3 was 115, and the amplitude was 40. The transition bin at the top of the continuous powder feeding device can be used for continuously filling and vacuumizing without influencing the plasma powder spheroidizing process. In the step 4, the total flow of the carrier gas and the dispersion gas is 10slpm, the distance between the powder outflow position and the plasma center position is 20mm, and the powder flow is 2.6 Kg/h. FIG. 5 is a graph showing the morphology of the spherical powder obtained in example 4.
Example 5:
the embodiment of the invention provides a rapid large-scale preparation method of fine-particle-size spherical powder for 3D printing, which comprises the following steps:
step 1: purchasing powder in a required particle size range or screening the purchased powder by using a vibrating screen to obtain powder in the required particle size range;
step 2: adjusting parameters to obtain stably running plasma;
and step 3: conveying the powder by using a continuous powder feeding device;
and 4, step 4: and melting the powder by using high-temperature plasma, and adjusting parameters to obtain the powder with high spheroidization rate.
Among them, in this embodiment: the granularity of the die steel powder purchased in the step 1 is less than 100 um; the operation parameters of stabilizing the plasma in the step 2 are that the total flow rate of plasma gas is 70slpm, the plasma power is 40kW, the flow rate of protective gas is 3slpm, and the pressure in the reactor is 15 psia; the vibration frequency of the vibration powder feeder used in step 3 was 125, and the amplitude was 55. The transition bin at the top of the continuous powder feeding device can be used for continuously filling and vacuumizing without influencing the plasma powder spheroidizing process. In the step 4, the total flow of the carrier gas and the dispersion gas is 10slpm, the distance between the powder outflow position and the plasma center position is 20mm, and the powder flow is 3 Kg/h.
It should be noted that, according to the preferred method for rapidly preparing the spherical powder with the fine particle size for 3D printing, the powder purchased in the step 1 is smaller than 150 meshes, or the purchased powder is sieved by a 150-mesh vibrating screen; the parameters of stable operation of the plasma in the 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 frequency of the vibration powder feeder used in the step 3 is 90-150, and the amplitude is 30-80; in the step 4, the total flow of the carrier gas and the dispersing gas is 1-20 slpm, the distance between the powder outflow position and the plasma center position is 0-50 mm, and the purpose of the invention can be realized when the powder flow is 0.5-9 Kg/h.
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.