JPH11256367A - Method for removing ti base coating film and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for removing a Ti-base coating film and its device by which the Ti-base coating film is efficiently removed. SOLUTION: A holding table 2 holding a member 11 coated with a Ti-base coating film is provided at the bottom of a treating tank 1, a driving motor 3 for rotating the table 2 at a fixed speed is connected to the table 2 and plural spray guns 4 are provided on the wall parts of the tank 1 so that these nozzles 4a are directed toward the center of the tank 1. The spray guns 4 are connected respectively to a storage tank 5 storing an aq. soln. 10 contg. hydrogen peroxide and 5 wt.% alkali hydroxide and an alkali hydroxide soln feeder 6 for supplying the alkali hydroxide soln. of specified concn. for every prescribed time as much as the specified amts. and an aq. hydrogen peroxide feeder 7 for supplying the aq. hydrogen peroxide of specified concn. for every prescribed time as much as the specified amts. are respectively connected to the tank 5. Meanwhile, the suction port of a recovery pipe 8 provided with a recovery pump 9 is connected to the bottom of the storage tank 5 and the delivery port of the recovery pipe 8 is connected to the tank 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for removing a Ti-based film, and is particularly effective when applied when removing a TiAlN film.

[0002]

2. Description of the Related Art Cutting tools obtained by coating a high-speed tool steel with a Ti-based coating have been widely used in recent years because of their excellent wear resistance. In such a cutting tool, as the coating is used, the coating on the blade part wears out faster than the coating on other parts. Therefore, after using for a predetermined time, all the coating is removed once and the blade part is ground. After re-adjustment, it is recycled by coating again. In the coating step, when the coated film deviates from the standard value, the film is completely removed and then coated again to be recycled.

[0003] In the removal of the Ti-based coating in such recycling, for example, Japanese Patent Application Laid-Open No. H5-
In Japanese Patent Publication No. 112885, a polymerized alkaline phosphate is used in an amount of 1 to 1.
20% by weight, 1 to 10% by weight of at least one alkali metal salt of a hydroxycarbonate organic acid, 2 to 15% by weight of an alkali salt of ethylenediamine / acetic acid, 0.1% by weight of an alkali hydroxide.
In a mixed aqueous solution containing 1 to 5% by weight and 3 to 7% by weight of hydrogen peroxide, a Ti-based coating (Ti
It discloses that a Ti-based coating can be removed by immersing (12 hours) a cutting tool coated with N, TiC, TiCN, and Ti) in a temperature range of 10 to 40 ° C.

[0004]

However, if the Ti-based film is removed by immersion in an aqueous solution as disclosed in Japanese Patent Application Laid-Open No. 5-112885, it takes a long time to remove the film. (Coating removal rate: 0.3
μm / h or less), and the processing efficiency was poor. In particular, TiAl
In the case of removing the N film, the film cannot be removed even when immersed for 60 hours (film removal speed: less than 0.1 μm / h).
It must be soaked for a long time using a large amount of aqueous solution.

[0005] When a member coated with a Ti-based film is large or has a complicated shape, a large amount of aqueous solution is required to immerse the member, resulting in a high chemical cost.

In view of the above, an object of the present invention is to provide a method and an apparatus for removing a Ti-based coating capable of efficiently removing the Ti-based coating at low cost.

[0007]

In order to solve the above-mentioned problems, a method for removing a Ti-based film according to the present invention comprises a method of coating a member coated with a Ti-based film containing hydrogen peroxide and alkali hydroxide. The Ti-based coating is removed from the member by spraying an aqueous solution containing more than 5% by weight.

Further, in order to solve the above-mentioned problems, a Ti-based film removing apparatus according to the present invention comprises a member coated with a Ti-based film containing hydrogen peroxide and 5% by weight of alkali hydroxide. It is characterized by comprising an aqueous solution spraying means for spraying an aqueous solution containing over the aqueous solution.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method and an apparatus for removing a Ti-based film according to the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of the apparatus.

[0010] As shown in FIG.
A holding table 2 for detachably holding a member 11 coated with a Ti-based coating is rotatably provided.
A drive motor 3 for rotating the holding table 2 at a constant speed is connected to the holding table 2.

The wall of the processing tank 1 is provided with the processing tank 1
A plurality of spray guns 4 with the tip of the nozzle 4a directed toward the inner central portion at predetermined intervals in the circumferential direction and the height direction of the tank 1 (in this embodiment, four directions at equal intervals around the circumference,
(Upper and lower two stages, a total of eight). The inlets of the spray guns 4 are connected to storage tanks 5 for storing an aqueous solution 10 containing hydrogen peroxide and containing alkali hydroxide in an amount exceeding 5% by weight. Storage tank 5
Is an alkali hydroxide supply means for supplying an alkali hydroxide solution such as a potassium hydroxide solution or a sodium hydroxide solution having a predetermined concentration into the storage tank 5 at predetermined time intervals. The supply device 6 is in communication with a hydrogen peroxide solution supply device 7 which is a hydrogen peroxide supply means for supplying a predetermined amount of hydrogen peroxide solution of a predetermined concentration into the storage tank 5 at predetermined time intervals.

A suction port of a recovery pipe 8 provided with a recovery pump 9 is connected to the bottom of the storage tank 5. The outlet of the collection pipe 8 communicates with the storage tank 5.

In this embodiment, the spraying uniformizing means is constituted by the holding table 2, the driving motor 3, and the like.
The spray gun 4, the storage tank 5, the alkali hydroxide solution supply device 6, the hydrogen peroxide solution supply device 7 and the like constitute an aqueous solution spraying unit, and the treatment tank 1, the collection pipe 8, the collection pump 9 and the like constitute an aqueous solution collection unit. doing.

Next, a method of removing a Ti-based film using such a removing apparatus will be described. When the member 11 coated with the Ti-based coating is held on the holding table 2, the driving motor 3 is driven to rotate the holding table 2 at a constant speed, and the spray gun 4 is operated to move the storage tank 5 from the nozzle 4a. When the aqueous solution 10 in the inside is sprayed toward the member 11, the aqueous solution 10 is evenly sprayed on the member 11,
The Ti-based film is efficiently removed from the member 11 (depending on the shape and thickness of the base material, but about 10 to 30 hours).

The aqueous solution 10 sprayed on the member 11
Is collected from the bottom of the processing tank 1 by the collection pump 9 to the collection pipe 8.
Is collected in the storage tank 5 via the supply unit, and the alkali hydroxide solution supply device 6 and the hydrogen peroxide solution supply device 7 replenish the alkali hydroxide and the hydrogen peroxide solution of a predetermined concentration by a predetermined amount at predetermined time intervals. Is adjusted to the original concentration and reused.

Therefore, the time required for removing the Ti-based coating from the member 11 can be significantly reduced, and the aqueous solution 10 can be used efficiently, so that the processing cost can be reduced. . In particular, in the case of the TiAlN film, it has conventionally been necessary to use a large amount of a chemical for a long time, but if the treatment is performed as described above, even the minimum necessary chemical can be completely removed in a short time.

Here, if the concentration of the alkali hydroxide in the aqueous solution 10 is 5% by weight or less, the Ti-based film cannot be removed efficiently.

The concentration of hydrogen peroxide in the aqueous solution 10 is not particularly limited, but may be 0.1-60%.
Is preferably within the range.

If the temperature of the aqueous solution 10 sprayed on the member 11 is lower than 10 ° C., the film removal rate is reduced. If the temperature is higher than 80 ° C., the concentration of the aqueous solution changes rapidly due to the self-reaction of the removing agent and the removal. Since the speed cannot be maintained, it is preferable to spray the aqueous solution 10 while maintaining the aqueous solution 10 at a temperature of 10 to 80 ° C. In particular, when the temperature of the aqueous solution 10 is 40 ° C. or higher, it can be more efficiently removed than when the temperature is lower than 40 ° C.

When potassium hydroxide is used as the alkali hydroxide, the surface of the base material is not roughened.
This is more preferable because it is possible to prevent a decrease in the adhesion of the Ti-based film to the base material during recoating.

In the above-mentioned Japanese Patent Application Laid-Open No. Hei 5-112885, the concentration of alkali hydroxide in the aqueous solution is 5% by weight.
It is stated that the removal speed becomes slower and the surface of the base material becomes discolored black when the above is reached. However, when potassium hydroxide is used in the TiAlN coating, such a phenomenon does not occur, and a favorable The result can be obtained.

[0022]

EXAMPLES In order to confirm the effects of the method and apparatus for removing a Ti-based film according to the present invention, the following confirmation experiments were conducted based on the above-described embodiment.

[Test Example 1] <Test Method> Flat plate (size: 20 × 20) of high-speed tool steel coated with a TiAlN film (film thickness: 5 μm)
× 5 mm) was sprayed with an aqueous solution (100 cc) containing 19% by weight of hydrogen peroxide and 13% by weight of potassium hydroxide for 10 hours.

<Test Results> After the test was completed, the TiAlN film was completely removed without remaining (coating removal rate: 0.5 μm / h).

[Test Example 2] <Test Method> A hob (outer diameter: 10) of a high-speed tool steel having a blade portion coated with a TiAlN film (film thickness: 2 to 8 μm)
0mm, length 150mm) and 19% by weight of hydrogen peroxide
An aqueous solution (800 cc) containing 13% by weight of potassium hydroxide was sprayed for 30 hours. Note that the rotation speed of the holding table 2 was 6 rpm.

<Test Results> After the test was completed, the TiAlN film was completely removed without remaining (coating removal rate: 0.25 μm / h or more).

[0027]

The method for removing a Ti-based coating according to the present invention comprises:
By spraying an aqueous solution containing hydrogen peroxide and containing alkali hydroxide in excess of 5% by weight onto the member coated with the Ti-based coating, the T
Since the i-based coating is removed, the Ti-based coating can be efficiently removed from the member with the minimum necessary aqueous solution, so that the time required for removing the Ti-based coating from the member can be greatly reduced. At the same time, the cost for processing can be reduced. In particular, in the case of a TiAlN coating, it has conventionally been necessary to use a large amount of a chemical for a long time, but according to this method, it is possible to completely remove the TiAlN coating in a short time even with a necessary minimum amount.

The apparatus for removing a Ti-based coating according to the present invention is characterized in that the member coated with the Ti-based coating is sprayed with an aqueous solution containing hydrogen peroxide and containing more than 5% by weight of alkali hydroxide. Since the spraying means is provided, when the aqueous solution is sprayed on the member coated with the Ti-based coating by the aqueous solution spraying means, the Ti-based coating can be efficiently removed from the member with a minimum necessary aqueous solution. Can significantly reduce the time required for the removal processing of the Ti-based coating, and can reduce the cost required for the processing. In particular, in the case of a TiAlN film, it has conventionally been necessary to use a large amount of chemicals for a long time, but with the use of the apparatus, even a necessary minimum amount can be completely removed in a short time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an apparatus for removing a Ti-based film according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing tank 2 Holding table 3 Drive motor 4 Spray gun 4a Nozzle 5 Storage tank 6 Alkali hydroxide solution supply device 7 Hydrogen peroxide solution supply device 8 Recovery pipe 9 Recovery pump 10 Aqueous solution 11 Member

Claims (2)

[Claims] 1. A member coated with a Ti-based coating is sprayed with an aqueous solution containing hydrogen peroxide and containing more than 5% by weight of alkali hydroxide to remove the Ti-based coating from the member. A method for removing a Ti-based coating. 2. A member coated with a Ti-based film is provided with an aqueous solution spraying means for spraying an aqueous solution containing hydrogen peroxide and containing alkali hydroxide in an amount exceeding 5% by weight. Equipment for removing Ti-based coatings.