CN110899716B

CN110899716B - Low-oxygen spherical Al powder and preparation method thereof

Info

Publication number: CN110899716B
Application number: CN201911296936.2A
Authority: CN
Inventors: 李利利; 丁照崇; 曹晓萌; 万小勇; 李勇军; 庞欣; 熊晓东; 贾倩; 张延宾; 曲鹏
Original assignee: Grikin Advanced Material Co Ltd
Current assignee: Grikin Advanced Material Co Ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2022-05-27
Anticipated expiration: 2039-12-17
Also published as: CN110899716A

Abstract

The invention discloses low-oxygen spherical Al powder and a manufacturing method thereof, belonging to the technical field of powder metallurgy. The Al powder is prepared by processing a high-purity Al ingot with the purity of not less than 99.9995 percent as a raw material into a cylindrical blank through a cold forging process, wherein the deformation of the ingot is more than 65 percent, then preparing an Al electrode rod, and preparing the low-oxygen spherical Al powder by adopting a plasma rotary electrode atomization method. The purity of the prepared powder is more than or equal to 99.999 percent, the oxygen content is less than 100ppm, the sphericity can reach more than 90 percent, the compactness and the mechanical property of the powder metallurgy metal product are improved, and the use requirement of the special high-purity metal alloy is met.

Description

Low-oxygen spherical Al powder and preparation method thereof

Technical Field

The invention belongs to the field of powder metallurgy, and particularly relates to low-oxygen spherical Al powder and a manufacturing method thereof.

Background

There are many methods for producing metal powder, such as mechanical methods (ball milling, grinding, etc.), physical methods (atomization), and chemical methods (reduction, electrolysis, carbonyl, substitution, etc.). However, in order to produce spherical metal powder, the metal powder production method generally employed is an atomization method, and specifically includes a water atomization method, a gas atomization method, a plasma atomization method, and a plasma rotary electrode atomization method. The existing preparation method of the Al powder comprises the following steps: ball milling, water atomization, and gas atomization. Wherein, the ball milling method is easy to introduce impurities into the powder, and the purity of the powder is low; the purity of the powder prepared by the water atomization method and the gas atomization method is relatively high, but hollow spheres and satellite spheres are easy to appear, impurities are inevitably introduced by using a crucible in the powder preparation process, high-purity powder cannot be obtained, Al is easy to oxidize, and the oxygen content of the prepared powder is higher than 500ppm no matter what purity Al raw material is adopted, so that the low-oxygen high-purity spherical Al powder cannot be prepared by the existing methods. In the preparation method of spherical metal powder, the sphericity of the powder prepared by the plasma rotating electrode is highest, the granularity is narrow, no hollow sphere or satellite sphere exists, the oxygenation is lowest, the used electrode bar can be directly used for preparing the powder only by meeting certain density, and the pure aluminum material is soft and easy to deform during rotation, so that the method for preparing the powder by high-speed rotating spheroidization is limited, and the problem cannot be solved by adopting the conventional powder preparation parameters of the plasma rotating electrode method.

Disclosure of Invention

Aiming at the problems, the invention provides low-oxygen spherical Al powder, wherein the purity of the Al powder is more than or equal to 99.999 percent, the oxygen content is less than 100ppm, and the sphericity is more than 90 percent.

A method for manufacturing low-oxygen spherical Al powder comprises the following steps:

1) processing an Al ingot into a cylindrical blank by taking a high-purity Al ingot as a raw material, wherein the purity of the Al ingot is more than or equal to 99.9995%, the oxygen content of the Al ingot is 10ppm, the diameter of the Al ingot is phi 180-phi 250mm, the length of the Al ingot is more than or equal to 180mm, the diameter of the blank is phi 105mm, the deformation of the Al ingot is more than or equal to 65%, and the processing technology is a cold forging technology;

2) machining the cold-forged blank obtained in the step 1) to prepare an Al electrode bar, wherein the size of the Al electrode bar is phi 100 mm/500 mm;

3) taking the Al electrode bar obtained in the step 2) as a raw material, and preparing powder by adopting a plasma rotary electrode atomization method, wherein the rotating speed of the Al electrode bar is 5000-15000 r/min, and the granularity D50 of the prepared Al powder is 100-400 microns.

The cold forging process in the step 1) is to adopt a cold forging press for processing.

The surface roughness Ra of the Al electrode bar in the step 2) is less than or equal to 0.8 mu m.

When the powder is prepared by the plasma rotary electrode atomization method in the step 3), the inert gas in the atomization chamber is argon with the purity of more than or equal to 99.99%, and the working pressure of the inert gas is 0.02-0.05 MPa.

The invention has the beneficial effects that:

1. the invention adopts a plasma rotating electrode atomization method to carry out spheroidizing powder preparation, and simultaneously carries out cold forging deformation strengthening on high-purity Al ingots aiming at the characteristics that pure aluminum materials are soft, are easy to deform during rotation and cannot rotate at high speed to carry out spheroidizing powder preparation.

2. The invention adopts a plasma rotating electrode atomization method to carry out spheroidizing powder preparation, and has no limit requirement on the density of the used electrode bar.

3. The powder prepared by the method has narrow granularity range, is easy to obtain target granularity powder, and can obviously improve the utilization rate of the powder; the sphericity is high, the powder fluidity is good, the powder spreading is more uniform, and the local defect caused by satellite balls or hollow balls is effectively avoided, so that the compactness and the mechanical property of the powder metallurgy metal product are improved; the high purity and low oxygen content of the powder can meet the use requirements of special high-purity metal alloys, such as high-purity Al alloy powder metallurgy targets.

Drawings

FIG. 1 is a flow chart of the manufacturing method of low-oxygen Al spherical powder according to the present invention;

Detailed Description

A low-oxygen spherical Al powder, the purity of the Al powder is more than or equal to 99.999 percent, the oxygen content is less than 100ppm, and the sphericity is more than 90 percent.

1) processing an Al ingot into a cylindrical blank by taking a high-purity Al ingot as a raw material, wherein the purity of the Al ingot is more than or equal to 99.9995%, the oxygen content of the Al ingot is 10ppm, the diameter of the Al ingot is phi 180-phi 250mm, the length of the Al ingot is more than or equal to 180mm, the diameter of the blank is phi 105mm, the deformation of the Al ingot is more than or equal to 65%, and the processing technology is a cold forging technology; and a cold forging press is adopted for processing;

2) machining the cold-forged blank obtained in the step 1) to prepare an Al electrode bar, wherein the size of the Al electrode bar is phi 100 mm/500 mm, and the surface roughness Ra of the Al electrode bar is less than or equal to 0.8 mu m;

3) preparing powder by using the Al electrode rod obtained in the step 2) as a raw material and adopting a plasma rotary electrode atomization method, wherein the rotating speed of the Al electrode rod is 5000-15000 r/min, and the granularity D50 of the prepared Al powder is 100-400 mu m; when the powder is prepared by the plasma rotary electrode atomization method, the inert gas in the atomization chamber is argon with the purity of more than or equal to 99.99%, and the working pressure of the inert gas is 0.02-0.05 MPa.

Aiming at the properties of soft aluminum material, easy deformation during rotation and the like, the hardness of the Al material cannot be improved to a great extent by the forging method in the prior art, but the powder preparation by applying the Al powder material to the plasma rotating electrode atomization method is realized by combining the cold forging process with the process flow and parameters of the preparation method.

The invention is described in further detail below with reference to the following figures and specific examples:

al powder was prepared according to the procedure shown in FIG. 1,

1) taking a high-purity Al ingot with the purity of more than or equal to 99.9995 percent, the oxygen content of 10ppm and the diameter of phi 180mm to phi 250mm as a raw material, processing the Al ingot into a cylindrical blank by adopting a cold forging processing mode, wherein the diameter of the forged blank is phi 105 mm;

2) machining the cold-forged blank to prepare an Al electrode bar with the surface roughness Ra of more than or equal to 0.8 mu m and the size phi of 100mm x 500 mm; the shorter the length of the Al electrode rod is, the less the Al electrode rod is difficult to rotate and deform, but the powder preparation efficiency needs to be considered in production, and experimental results show that the length of the electrode rod can reach 500 mm;

3) if the rotating speed is too low, the particle size of the powder is obviously increased, the requirement on the particle size of the Al powder is not met, and if the rotating speed is too high, the oxygen content of the powder is increased, and the Al electrode rod has the risk of rotating deformation, so that the sphericity of the powder is reduced; therefore, a plasma rotating electrode atomization method is adopted, and Al electrode rods with the diameter of phi 100mm are used as raw materials to carry out spheroidization powder preparation, wherein the rotating speed of the Al electrode rods is 5000 r/min-15000 r/min;

the main manufacturing process and performance results of the Al powder in the inventive examples 1-6 are shown in Table 1.

TABLE 1 examples 1-6 main manufacturing process and properties of Al powders

Claims

1. The manufacturing method of the low-oxygen spherical Al powder is characterized in that the purity of the Al powder is more than or equal to 99.999 percent, the oxygen content is less than 100ppm, and the sphericity is more than 90 percent;

the manufacturing method comprises the following steps:

1) processing an Al ingot into a cylindrical blank by taking a high-purity Al ingot as a raw material, wherein the purity of the Al ingot is more than or equal to 99.9995%, the oxygen content of the Al ingot is 10ppm, the diameter of the Al ingot is phi 180 mm-phi 250mm, the length of the Al ingot is more than or equal to 180mm, the diameter of the blank is phi 105mm, the deformation of the Al ingot is more than or equal to 65%, and the processing technology is a cold forging technology;

3) and (3) preparing powder by using the Al electrode rod obtained in the step 2) as a raw material and adopting a plasma rotary electrode atomization method, wherein the rotating speed of the Al electrode rod is 5000-15000 r/min, and the granularity D50 of the prepared Al powder is 100-400 microns.

2. The manufacturing method of claim 1, wherein the cold forging process in step 1) is performed by using a cold forging press.

3. The manufacturing method according to claim 1, wherein the surface roughness Ra of the Al electrode bar in the step 2) is not more than 0.8 μm.

4. The manufacturing method according to claim 1, wherein in the step 3), when the powder is prepared by the plasma rotary electrode atomization method, the inert gas in the atomization chamber is argon with the purity of not less than 99.99%, and the working pressure of the inert gas is 0.02-0.05 MPa.