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CN-122007424-A - Preparation method of ultrathin tantalum electrode slice

CN122007424ACN 122007424 ACN122007424 ACN 122007424ACN-122007424-A

Abstract

The invention relates to the technical field of metal materials, in particular to a preparation method of an ultrathin tantalum electrode slice. The ultra-thin tantalum electrode sheet with the thickness of 0.18-0.22mm can be obtained by mixing tantalum powder with the D 50 -15 mu m and tantalum powder with the D 50 of 100-150 mu m according to the weight ratio of 4-6:6-4, carrying out heat treatment, oil pressure molding, two-stage vacuum vertical smelting, forging, high-temperature sintering rough rolling, vacuum heat treatment and finish rolling.

Inventors

  • LOU YUFENG
  • WEI DONGDONG
  • YAO LI
  • PAN RUI
  • LIAO XIN
  • WEI YUN

Assignees

  • 江西九岭锂业股份有限公司

Dates

Publication Date
20260512
Application Date
20260227

Claims (10)

  1. 1. The preparation method of the ultrathin tantalum electrode slice is characterized by comprising the following steps of: S1, mixing tantalum powder with the D 50 -15 mu m and tantalum powder with the D 50 of 100-150 mu m according to the weight ratio of 4-6:6-4, and preparing a tantalum strip green body through heat treatment and oil pressure molding; S2, carrying out two-section vacuum vertical melting on the tantalum strip green body prepared in the step S1, and forging and pressing the vertically melted tantalum strip to obtain a tantalum forging piece; s3, sintering the tantalum forging piece prepared in the step S2 at a high temperature in a vacuum horizontal graphite furnace, and rough rolling by adopting two rolling mills to obtain a tantalum rough rolling piece; And S4, carrying out vacuum heat treatment on the tantalum rough rolling piece, and carrying out non-reversing finish rolling by adopting a four-roller mirror mill to obtain the ultrathin tantalum electrode piece with the thickness of 0.18-0.22 mm.
  2. 2. The preparation method of the ultrathin tantalum electrode sheet according to claim 1, wherein in S1, the oil pressure molding method comprises the steps of loading tantalum powder into a mold, and pressing the tantalum powder into a tantalum strip green body with the size of 16 multiplied by 500mm by a powder molding oil press, wherein the molding pressure is 250-350MPa, and the molding time is 5-20S; The heat treatment method in S1 is to heat treat for 1-3h under the vacuum degree of less than 2X 10 -3 Pa and the temperature of 1080-1120 ℃.
  3. 3. The method for preparing the ultrathin tantalum electrode slice according to claim 1, wherein in S2, the two-stage vacuum vertical melting method is that a tantalum strip green body is placed in a vertical melting furnace, the vacuum degree is adjusted to be below 5 multiplied by 10 -3 Pa, the temperature is firstly increased to 1350-1450 ℃ at the speed of 5-10 ℃ per minute, the temperature is kept for 1-2h, the temperature is further increased to 2330-2370 ℃ and the temperature is kept for 2-4h.
  4. 4. The method for manufacturing the ultrathin tantalum electrode plate, as claimed in claim 1, is characterized in that in S2, the forging and pressing method is that a vertically melted tantalum strip is fixed in the middle of an oil press template, and is forged and pressed to be 8-12mm in thickness under the pressure of 200 MPa.
  5. 5. The method of claim 1, wherein S2 further comprises cutting the vertically melted tantalum strip into four segments prior to the forging.
  6. 6. The method for preparing the ultrathin tantalum electrode according to claim 1, wherein in the step S3, the high-temperature sintering method is that a tantalum forging piece is placed in a vacuum horizontal graphite furnace, the vacuum degree is regulated to be lower than 2X 10 -3 Pa, the temperature is increased to 1980-2020 ℃ at 5-10 ℃ per minute, and the heat preservation time is 1.5-2.5 hours.
  7. 7. The method for manufacturing an ultrathin tantalum electrode according to claim 1, wherein in the step S3, a two-roll mill with a diameter of 190×300mm is adopted, the pass deformation is 4.4-5%, and the thickness is 0.8-1.2mm.
  8. 8. The method for preparing the ultrathin tantalum electrode sheet according to claim 1, wherein in the step S4, the tantalum rough rolled piece is placed in a vacuum horizontal graphite furnace, the vacuum degree is regulated to be less than 2X 10 -3 Pa, the temperature is increased to 1180-1220 ℃ at 5-10 ℃ per min, and the heat preservation time is 50-70min.
  9. 9. The method for preparing the ultrathin tantalum electrode sheet according to claim 1, wherein in S4, the non-reversing finish rolling method comprises the steps of adopting a four-roller mirror mill with the diameter of 190 multiplied by 90 multiplied by 300mm to roll along the rough rolling feeding direction, wherein the pass deformation is 1.5-2%; The surface roughness Ra of the prepared ultrathin tantalum electrode slice is less than or equal to 0.1 mu m.
  10. 10. The method for preparing an ultrathin tantalum electrode according to claim 1, wherein, S2, after forging and pressing, pickling and drying are further included; s3, after rough rolling, trimming burrs, pickling, alkali washing and drying are further included; S4, after finish rolling, shearing, alkali washing, water washing and wiping are further included; wherein the acid adopted in the acid washing is mixed acid, and the mass ratio of nitric acid, sulfuric acid, hydrofluoric acid and water is 5:2:2:20; the alkali used for alkali washing is a washing powder solution with the concentration of 5 percent.

Description

Preparation method of ultrathin tantalum electrode slice Technical Field The invention relates to the technical field of metal materials, in particular to a preparation method of an ultrathin tantalum electrode slice. Background Tantalum metal has excellent dielectric properties, high temperature resistance and acid-base resistance, is a core element used in electronic equipment such as communication and computers in extreme environments, and with the development of miniaturization and high frequency of electronic equipment components, thinner, lower loss, good mechanical reliability and appearance consistency of tantalum metal sheets used in electronic equipment are required. An ultrathin tantalum electrode plate with the size of 0.2mm is a preferred scheme for considering the processability and the mechanical strength at present. The tantalum electrode with the thickness of 0.2 mm is usually prepared by adopting multiple electron beam smelting, sawing, cogging, rough rolling and finish rolling at present, and the process has the advantages that the finished product rate of the peeled tantalum ingot is only about 80 percent after the multiple high-vacuum high-temperature electron beam smelting, and the finished product rate is possibly less than 55 percent after the tantalum electrode with the thickness of 0.2 mm is processed. In addition, when the prior art is used for processing a thicker tantalum ingot into a thinner tantalum sheet, the problems of rough surface and poor mechanical and electrical properties of the sheet are easy to occur. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a preparation method of an ultrathin tantalum electrode slice, which can obtain a 0.2 mm-grade ultrathin tantalum electrode slice, and the prepared tantalum electrode slice has high yield, small thickness deviation, low surface roughness and excellent overall mechanical and electrical properties. In order to achieve the above purpose, the invention adopts the following technical scheme: The application provides a preparation method of an ultrathin tantalum electrode slice, which comprises the following steps: S1, mixing tantalum powder with the D 50 -15 mu m and tantalum powder with the D 50 of 100-150 mu m according to the weight ratio of 4-6:6-4, and preparing a tantalum strip green body through heat treatment and oil pressure molding; S2, carrying out two-section vacuum vertical melting on the tantalum strip green body prepared in the step S1, and forging and pressing the vertically melted tantalum strip to obtain a tantalum forging piece; s3, sintering the tantalum forging piece prepared in the step S2 at a high temperature in a vacuum horizontal graphite furnace, and rough rolling by adopting two rolling mills to obtain a tantalum rough rolling piece; And S4, carrying out vacuum heat treatment on the tantalum rough rolling piece, and carrying out non-reversing finish rolling by adopting a four-roller mirror mill to obtain the ultrathin tantalum electrode piece with the thickness of 0.18-0.22 mm. According to the preparation method of the tantalum electrode, provided by the application, the tantalum powder with the thickness of 0.18-0.22mm is prepared by mixing tantalum powder with the D 50 of 5-15 mu m and tantalum powder with the D 50 of 100-150 mu m according to the weight ratio of 4-6:6-4, and carrying out heat treatment, oil pressure forming, two-stage vacuum vertical melting, forging, high-temperature sintering rough rolling, vacuum heat treatment and finish rolling, and various technological parameters are optimized. Further, in S1, the oil pressure molding method is that tantalum powder is filled into a die, a powder molding oil press is adopted to press the tantalum powder into a tantalum strip green body with the size of 16 multiplied by 500mm, the molding pressure is 250-350MPa, the molding time is 5-20S, and the heat treatment method in S1 is that the heat treatment is carried out for 1-3h under the conditions that the vacuum degree is less than 2 multiplied by 10 -3 Pa and the temperature is 1080-1120 ℃. The tantalum powder can be purified and the plasticity of the tantalum powder is improved by heat treatment at the temperature, so that the tantalum strip green body with higher initial density and certain strength can be obtained by oil pressure molding, the tantalum strip green body is convenient to take, cracking and powder falling in the vertical melting process are avoided, the processability is strong, the appearance uniformity is good, the yield is high, and the mechanical property of the tantalum electrode plate is improved. Further, in S2, the two-stage vacuum vertical smelting method is that the tantalum strip green body is placed in a vertical smelting furnace, the vacuum degree is regulated to be lower than 5 multiplied by 10 -3 Pa, the temperature is firstly increased to 1350-1450 ℃ at the speed of 5-10 ℃ per minute, the temperature is kept for 1-