Search

CN-121992467-A - Process method for hard anodic oxidation film formation

CN121992467ACN 121992467 ACN121992467 ACN 121992467ACN-121992467-A

Abstract

The invention relates to a surface treatment method of a hard anode, which aims to solve the problems that the hard anode has long oxidation working time, large energy consumption in the process and the like in the treatment process, and provides a process method for forming a film by hard anode, comprising the steps of hanging up, degreasing, alkaline etching, stripping, anodic oxidation, hole sealing and hanging down, wherein an anodic oxidation tank solution for the anodic oxidation comprises 140-180g/L sulfuric acid, 48-120 g/L aluminum sulfate octadeca hydrate and 3-7g/L glycolic acid solution with the mass concentration of 25-30%, and/or the addition amount of sodium metasilicate in a hole sealing tank is 2-4g/L. Greatly improves the efficiency of the existing hard anodic oxidation process, reduces the production energy consumption and reduces the production cost.

Inventors

  • YU XIAOJIE
  • GAO XIAOBIN
  • XU MEILING
  • LI HUI
  • WANG ZHEJING

Assignees

  • 浙江先导精密机械有限公司

Dates

Publication Date
20260508
Application Date
20251230

Claims (10)

  1. 1. A process method for forming a film by hard anodic oxidation comprises the steps of hanging up, degreasing, alkaline etching, stripping, anodic oxidation, hole sealing and hanging down, and is characterized in that an anodic oxidation tank solution comprises sulfuric acid, aluminum sulfate octadeca hydrate and a glycollic acid solution with the mass concentration of 25-30%.
  2. 2. The process method for forming the hard anodic oxidation film according to claim 1, wherein sulfuric acid in the anodic oxidation tank liquor is 140-180g/L, aluminum sulfate octadeca hydrate is 48-120g/L, and a glycollic acid solution with mass concentration of 25-30% is 3-7g/L.
  3. 3. The process for forming a hard anodized film according to claim 1 or 2, characterized in that the anodizing is carried out at a temperature of-4 to 0 ℃, a current density of 1.5 to 2.5A/dm 2 and a time of 60 to 90min.
  4. 4. The process method for forming the hard anodic oxidation film is characterized by comprising the steps of hanging up, degreasing, alkaline etching, stripping the film, anodic oxidation, hole sealing and hanging down, and is characterized in that sodium metasilicate is included in hole sealing groove liquid.
  5. 5. The process of forming a film by hard anodic oxidation according to claim 4, wherein the addition amount of sodium metasilicate in the hole sealing groove is 2-4g/L.
  6. 6. The process of forming a hard anodic oxidation film according to claim 4 or 5, wherein the sealing temperature is 85-95 ℃ and the sealing time is 20-40min.
  7. 7. A process for forming a film by hard anodic oxidation comprises the steps of hanging up, degreasing, alkaline etching, stripping, anodic oxidation, hole sealing and hanging down, and is characterized in that an anodic oxidation tank solution comprises sulfuric acid, aluminum sulfate octadecanoate hydrate and an glycollic acid solution, and the hole sealing tank solution comprises sodium metasilicate.
  8. 8. The process method for forming the hard anodic oxidation film according to claim 7, wherein the addition amount of sodium metasilicate in the hole sealing groove is 2-4g/L, and the process method is characterized in that sulfuric acid in the anodic oxidation groove liquid is 140-180g/L, aluminum sulfate octadecahydrate is 48-120g/L, and a glycollic acid solution with mass concentration of 25-30% is 3-7 g/L.
  9. 9. The process for forming a hard anodized film according to claim 7 or 8, characterized in that the anodizing temperature is-4-0 ℃, the current density is 1.5-2.5A/dm 2 , and the time is 60-90min.
  10. 10. The process for forming a hard anodic oxidation film according to claim 7 or 8, wherein the sealing temperature is 85-95 ℃ and the sealing time is 20-40min.

Description

Process method for hard anodic oxidation film formation Technical Field The invention relates to a surface treatment method of a hard anode, in particular to a process method for forming a film by hard anode oxidation. Background Hard anodic oxidation is a surface treatment technique that electrochemically produces a hard anodic oxide film on the metal surface, typically over 50um in thickness, some up to 100um in thickness. The oxide film has excellent corrosion resistance, wear resistance and insulativity, and is widely applied to the fields of aerospace, automobile manufacturing, semiconductor equipment, medical appliances and the like. In the hard anodic oxidation process, a metal workpiece is used as an anode and is placed in electrolyte, and a direct current, an alternating current or a pulse current is applied to enable the metal surface to undergo oxidation reaction, so that a compact oxide film is generated. The electrolyte is usually sulfuric acid solution or mixed acid (mixed acid) solution, and is matched with a low-temperature bath environment, and the proportion and concentration of different components have important influence on the performance of an oxide film, the process operation time and the like. At present, the hard anodic oxidation is increasingly widely applied in industry, particularly in the semiconductor equipment industry, and is widely applied to the process, but the problems of long oxidation working time, high energy consumption in the process and the like are commonly existed in the treatment process. The film thickness is usually required to be more than 50um, the common oxidation working solution is proportioned, the growth rate of the oxidation film is 0.2um/min-0.3um/min, the oxidation time is 3-4.5 hours, and therefore, a plurality of stations and rectifiers are required to be configured for one oxidation line to meet the production. In order to better control the thickness of the oxide film, a constant current working mode is generally adopted in the conventional hard anodic oxidation process, the current is kept unchanged in the whole operation process, but as the thickness of the oxide film is increased, the product resistance is gradually increased, the hard anodic oxidation working voltage is gradually increased along with the working time, the thickness of the film is more than 50um, the voltage can reach about 150V generally, and the power consumption is rapidly increased along with the time increase. Meanwhile, in the process of hard anodic oxidation, huge heat energy is generated, and in order to keep the low-temperature state of the bath solution, strong cooling is needed synchronously, and the ice water machine keeps the running state at all times. And the hole sealing time is long by matching with the traditional pure water, generally more than 4 hours are needed, the hole sealing temperature is high, and the hole sealing temperature must reach more than 95 ℃. Disclosure of Invention In order to solve the problems that the oxidation working time is long, the energy consumption in the process is large and the like in the process of hard anodic oxidation, the invention provides a process method for forming a film by hard anodic oxidation, which greatly improves the efficiency of the existing hard anodic oxidation process, reduces the production energy consumption and reduces the production cost. The invention is realized by the following technical scheme, and the process method for rapidly forming the film by hard anodic oxidation comprises the steps of conventionally used upward hanging-degreasing-alkaline etching-film stripping-anodic oxidation-hole sealing-downward hanging, wherein anodic oxidation bath liquid for anodic oxidation comprises sulfuric acid, aluminum sulfate octadeca hydrate and an glycollic acid solution with the mass concentration of 25-30%, the use amount is 140-180g/L of sulfuric acid, 48-120g/L of aluminum sulfate octadeca hydrate and 3-7g/L of glycollic acid solution with the mass concentration of 25-30%. Preferably, the anodic oxidation tank liquor is mixed and then placed into the oxidation tank liquor for anodic oxidation, the temperature is between-4 and 0 ℃, the current density is between 1.5 and 2.5A/dm 2, and the time is between 60 and 90 minutes. The oxide film growing process is a process that a workpiece generates alumina at an anode and electrolytic oxygen, and the alumina is dissolved by synchronizing the reaction of an oxidation tank solution and the alumina, and when the oxide film generating rate is larger than the dissolving rate, the oxide film thickness is increased and increased along with time. According to the invention, different additives are added into the traditional sulfuric acid anodic oxidation tank liquid to increase the formation rate of the oxide film and reduce the dissolution rate of the oxide film so as to solve the problem of long oxidation time. A process for quickly forming film by hard anodic oxidati