JP5353310B2 - Vanadium-containing coating and mold or cutting tool coated with vanadium-containing coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vanadium-containing film, even if the wear of a film is generated, which can prevent the damage of a die and a tool, and to provide a die and a tool coated with the vanadium-containing film. <P>SOLUTION: The vanadium-containing film is a film coated on a base material made of an iron-based alloy and expressed by V<SB>(1-X)</SB>C<SB>X</SB>, wherein X lies in the range of &gt;70 to 95 at%. Further, the die and tool are obtained by coating the surface of a base material made of an iron-based alloy with a composite film made of a V film and a V<SB>(1-Y)</SB>C<SB>Y</SB>film (wherein, Y is atomic% and lies in the range of 40 to 60 at%), and thereafter coating the film with a vanadium-containing film expressed by V<SB>(1-X)</SB>C<SB>X</SB>(wherein, X lies in the range of &gt;70 to 95 at%). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a coating containing V (vanadium) and a mold or a cutting tool coated with the coating.

     Among general industrial equipment, machine parts with sliding are required to have wear resistance and durability, and various coatings (films) are applied to the surfaces of these machine parts. In particular, TiN (titanium nitride) coating and CrN (chromium nitride) coating have high coating hardness and are excellent in wear resistance, and are widely used for dies and tools. DLC (diamond-like carbon) coatings are also frequently used in dies and tools because they have a lower coefficient of friction than other coatings and are excellent in wear resistance.

    However, a mold or a tool coated with a TiN coating or a CrN coating has a problem that the coating is easy to peel off when the coating is applied to a mold or a tool with a thick film because the internal stress of the coating is high. In particular, since the internal stress of the DLC film is larger than that of other films, it is difficult to increase the thickness of the film alone. Therefore, contrivances have been made such as stress relaxation by sandwiching an intermediate layer between the mold or tool surface and the DLC film, but the problem that the DLC film easily peels is still not solved.

Therefore, a coating such as VC (Vanadium Carbide) has been devised as one of the coatings that have wear resistance and durability and are difficult to peel even if they are thick. For example, Patent Document 1 discloses that adhesion of a film and excellent wear resistance are obtained by coating a film containing VC on a mold or a tool. Patent Document 2 discloses that a tool coated with a VN (vanadium nitride) coating or a VCN (vanadium carbonitride) coating can suppress deformation due to high-temperature heating and shape change due to a thick film.

Japanese Patent No. 3909658 JP 2005-46975 A

  However, when the surface coatings shown in Patent Document 1 and Patent Document 2 are VC, VN, and VCN, when a molding process using a mold, a cutting process using a tool, or the like is performed, the material to be contacted (the counterpart material) As a result of adhesion to the surface of the molding material or work material and part of the coating disappearing (wearing) when leaving the surface of the mating material, there is a problem that the mold or tool surface is exposed.

In addition, since coatings such as VC and VN have a metallic luster, even if the mold or tool surface is exposed as a result of wear of the coating during use, the mold or tool is made of an iron alloy base. In the case of a material, since the coating such as VC or VN and the base material made of an iron-based alloy have metallic luster, it cannot be determined whether the coating is worn or not. Therefore, as a result of continuing to use the mold or tool while the coating is worn, there is a problem that the mold or tool is damaged.

Further, in the claims of Patent Document 2, when X and Y are V (vanadium) and C (carbon) atomic% (at%), V _X (C _Y N _1-Y ) _1-X In the film, the range X of atomic% of V is limited to 30 at% or more and 80 at% or less. In other words, when the film does not contain N, the range of atomic% of C is limited to 20 at% or more and 70 at% or less, but the reason and grounds are not disclosed in the specification. Also, in the examples, only examples of coatings of three modes of VC, VN, and VC ₃ N ₇ are disclosed, and effects on other coating modes are unclear.

  In view of the above-described problems, an object of the present invention is to provide a coating that can reduce the wear on the surface of a counterpart material even when a molding process using a mold or a cutting process using a tool is performed. Another object of the present invention is to provide a coating that can prevent damage to iron-based alloy substrates such as dies and tools even if the coating is worn.

As a result of diligent research, the present inventor has determined that X (atomic%), which is the composition ratio of C in the film made of V _(1-X) C _X , is the friction of the film depending on the value of X as shown in FIG. The coefficient changes. And the change point exists in the place which exceeded the range of 40 at% or more and 60 at% or less which is the range of conventional X. Furthermore, it has been found that the friction coefficient of the coating having a C composition ratio X of more than 70 at% and not more than 95 at% is superior to that of the coating of 70 at% or less and shows excellent lubricity. . Furthermore, _V represented by VC coating on iron-based alloy base material _{(1-Y) C Y} coatings (where, Y is less 40 at% or more 60at% in atomic%) when coated directly, VC coating likewise V _{(1-Y) C} Y film is easy to peel. Therefore, after coating the V film on ferrous alloy substrate, by covering the V _(1-Y) C _Y film, adhesion of V _(1-Y) C _Y coating to iron-based alloy substrate Increases nature. _{Further, V (1-Y) C} Y film has a metallic luster like the iron-based alloy substrate _{but, V (1-X) C} X film (X is 70 at% super 95 at% in atomic% The appearance of the following is gray or black. _{Therefore, V (1-Y) C} Y when coating on the coated and _{V (1-X) C} X _{coating, V (1-X) C} X coating _V having metallic luster when worn _(1-Y) A _CY film appears. _{Or, V (1-Y) C} even _Y film is worn with _{V (1-X) C} X film, for its part having a metallic luster due to iron-based alloy substrate, resulting in _{V (1-X )} and the wear of C _X film become known that can be easily visually confirmed.

Based on this knowledge, in the present invention, it is a coating film coated on a base material made of an iron-based alloy, consisting of V _(1-X) C _X , and X is more than 70 at% and not more than 95 at% in atomic%. It is a vanadium-containing film , and a composite film is coated between the iron-based alloy substrate and the vanadium-containing film, and the composite film is a V film, V _{(1-Y) in} order from the iron-based alloy substrate. C _Y coatings (where, Y is 60at% or less than 40 at% in atomic percent) to solve the problems described above by providing a coating comprising.

That is, it is a film made of V _(1-X) C _X whose composition ratio of C is more than 70 at% and not more than 95 at%, and the composite film is coated between the iron alloy base material and the vanadium-containing film. cage, coating a composite coating V coating order of proximity to the iron-based alloy base _{material, V (1-Y) C Y} coatings (where, Y is 60at% or less than 40 at% in atomic percent), excellent lubricity Indicates. The reason for limiting the range of the composition ratio of C is based on the pin-on-disk test results shown in FIG. 3 as described above.

The invention according to claim 2 is the mold or cutting tool having the coating according to claim 1 and the iron-based alloy substrate coated with a vanadium-containing coating that is a mold or a cutting tool.

_V represented by VC coating on the iron-based alloy base material _{(1-Y) C Y} coatings (where, Y is more than 40 at% 60at% or less in atomic%) when coated directly, VC coating likewise _{V ( 1-Y) The CY} coating is easy to peel off. Therefore, after coating the V film on ferrous alloy substrate, by covering the V _(1-Y) C _Y film, adhesion of V _(1-Y) C _Y coating to iron-based alloy substrate Increases nature. Further, the V _{(1-Y) CY} coating has a metallic luster similar to the iron alloy base material, but the V _(1-X) C _X coating (X is an atom _{) of the} invention according to claim 1. The appearance of 70% to 95% by weight) is gray or black. _{Therefore, V (1-Y) C} Y when coating on the coated and _{V (1-X) C} X _{coating, V (1-X) C} X coating _V having metallic luster when worn _(1-Y) A _CY film appears. Alternatively, even if the V _{(1-Y) CY} coating is worn together with the V _(1-X) C _X coating, the portion has a metallic luster due to the iron-based alloy base material, and as a result, according to claim 1 The wear of the V _(1-X) C _X coating of the invention can be easily visually confirmed.

In the present invention, it is a film coated on a base material made of an iron-based alloy , which is composed of V _(1-X) C _X , and X is a vanadium-containing film having an atomic% of more than 70 at% and not more than 95 at%. there are, the composite coating is coated between the iron-based alloy base material and the vanadium-containing film, sequentially V coat composite coating is close to the iron-based alloy base _{material, V (1-Y) C} Y coatings ( However, since Y is a film composed of 40 at% or more and 60 at% or less in atomic%), it has a low friction coefficient and excellent lubricity. Therefore, even if molding processing with a mold or cutting processing with a cutting tool is performed Abrasion with the material surface can be reduced. Further, since V _(1-Y) C _Y film having a metallic luster when the vanadium-containing film a is V _(1-X) of the gray or black C _X film is worn appears, can be easily confirmed visually that part . Therefore, the use of the mold and the cutting tool can be stopped immediately, and the mold and the cutting tool can be prevented from being damaged by using the mold and the cutting tool surface exposed.

Further, in the invention of claim 2, by using a mold coated with the vanadium-containing film having the film of claim 1, the vanadium-containing film has a low friction coefficient and excellent lubricity, so that the mold release property is achieved. Can also be improved. Moreover, by using the cutting tool coated with the vanadium-containing coating having the coating according to claim 1, the wear of the coating can be reduced and the tool performance (life) can be improved.

In addition, since the V _{(1-Y) CY} film having a metallic luster appears when the gray or black V _(1-X) C _X film that is the vanadium-containing film according to the invention of claim 1 is worn, The part can be easily visually confirmed. Therefore, the use of the mold and the cutting tool can be stopped immediately, and the mold and the cutting tool can be prevented from being damaged by using the mold and the cutting tool surface exposed.

1 is a longitudinal sectional view of a melt evaporation type ion plating apparatus 10 used when coating a film such as a vanadium-containing film according to the present invention. (A) used in Example 1 which concerns on this invention is a schematic perspective view of the pin-on-disk test apparatus 11, (b) is a schematic top view of the test apparatus 11. FIG. In Example 1 according to the present invention, a disc-shaped test piece was coated with a V film, and then a vanadium-containing film composed of V _(1-X) C _X (X is 32 to 95 at% in atomic%) was coated with a pin. It is a graph which shows the measurement result of the friction coefficient of the film which performed the on-disk test. In Example 2 which concerns on this invention, it is a manufacturing process of the tablet 36 using the tableting machine 31. FIG.

  An example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a melt evaporation type ion plating apparatus 10 used for coating a film such as a vanadium-containing film according to the present invention. The melt evaporation type ion plating apparatus 10 includes a vacuum chamber 1 for performing a coating process, a focusing coil 2 attached to the outside of the chamber 1, a holocathode electron gun 3 for forming plasma in the chamber, and a plasma raw material. And a base material holder 5 for holding a base material (object to be processed) for coating the melted material that has become plasma.

A substrate to be coated is attached to the substrate holder 5 in the melt evaporation type ion plating apparatus 10, and the inside of the vacuum chamber 1 is evacuated to a pressure of 5 × 10 ⁻³ Pa or less using a vacuum pump. Do. Thereafter, a molten material such as vanadium metal in the crucible 4 is reacted with a hydrocarbon gas such as acetylene or ethylene introduced into the vacuum chamber 1 from a reaction gas inlet (not shown) while being in a plasma state by the holocathode type electron gun 3. Thus, a coating such as a vanadium-containing coating according to the present invention can be coated on the substrate surface.

In order to compare the friction coefficient with the vanadium-containing coating according to the present invention and other coatings, a frictional wear test was conducted. In this test, a disc-shaped test piece was coated with a V (vanadium) film using acetylene gas in the apparatus 10 shown in FIG. 1, and then a vanadium-containing film composed of V _(1-X) C _X (X is The test piece was subjected to a pin-on-disk test. 2A is a schematic perspective view of the pin-on-disk test apparatus 11, and FIG. 2B is a schematic plan view of the test apparatus 11.

Here, in the pin-on-disk test, as shown in FIG. 2 (a), the disk-shaped test piece 13 to be measured is rotated at a constant speed while pressing the pin 12 with a constant load, and the friction coefficient at that time is evaluated. Refers to a test. The pin-on-disk test was performed under the following conditions. The result is shown in FIG.
・ Test equipment C-SEM tribometer ・ Test speed 500rpm
・ Test time: 20 minutes ・ Rotating radius: 2 mm
・ Peripheral speed 0.1m / s
・ Load 10N
・ Specimen material High-speed tool steel (SKH51) surface is nitrided ・ Pin material Bearing steel (SUJ2: Tip diameter 6 mm)

FIG. 3 shows the vanadium-containing coating C made of V _(1-X) C _X after the V-coating is applied to the disk-shaped test piece 13 shown in FIGS. 2A and 2B in the pin-on-disk test described above. The measurement result of the coefficient of friction when the film in which the composition ratio X is changed in the range of 32 to 95 at% is coated is shown. As shown in FIG. 3, the friction coefficient of the coating having a C composition ratio X of 30 to 35 at% is approximately 0.8, and the coating having X increased from 52 to 54 at% is approximately 0.6 to 0.00. The value was around 7. Further, when X increased to about 60 at%, the friction coefficient decreased to about 0.2 to 0.3.

On the other hand, when the C composition ratio X corresponding to the coating according to the present invention exceeds 70 at%, the friction coefficient of the coating is less than 0.2, and even if X increases to 95 at%, the friction coefficient is 0.2. The result showed less than. From the above, the vanadium-containing film (X is more than 70 at% and not more than 95 at%) in V _(1-X) C _{X according} to the present invention can be applied to other films having a C composition ratio X of 70 at% or less. In comparison, the coefficient of friction was small. This indicates that the V _(1-X) C _X coating (X is more than 70 at% and not more than 95 at%) according to the present invention has excellent lubricity.

Next, the vanadium-containing coating according to the present invention is coated on the surface of the punch for tableting machine made of alloy tool steel (SKD61) by the same coating method as described above, and the coating life test is performed by tableting the powder. went. The results are shown in Table 1. FIG. 4 shows the manufacturing process of the tablet 36 using the tableting machine 31.

Table 1 shows the film life when a film life test is performed with a tableting machine on the bags A to C described later. The coating life test was performed by preparing the following three types of upper and lower eyelids at the tip of the upper and lower eyelids described later, and processing and molding a powder tablet. Specific coating modes are: (1) After coating the coating according to the present invention, that is, the V coating, ₆₀ C ₄₀ V on the coating ₂₅ C ₇₅ And a comparative example (2) a wrinkle without any coating (hereinafter referred to as B), and (3) a V coating and V ₆₀ C ₄₀ There were a total of three types of soot (hereinafter referred to as “C”) coated with a coating.

In FIG. 4, a tableting machine 31 is a machine for forming a tablet 36, and includes an upper punch 32, a lower punch 33, and a mortar 34. Further, the tip end portion of the lower punch 33 is disposed at the center of the die 34, and the surfaces of the tip portions of the upper punch 32 and the lower punch 33 are tableting molding surfaces. In the manufacturing process of the tablet 36, the powder 35, which is the raw material of the tablet 36, is placed in the mortar 34, the upper punch 32 is inserted into the mortar 34 from above the powder 35, and the upper and lower punches 32 and 33 are inserted. Then sandwich the powder 35. And the upper and lower ridges 32 and 33 are pressurized and the tablet 36 is shape | molded. Thereafter, the upper punch 32 is removed from the die 34 and the tip of the lower punch 33 is pushed up together with the tablets 36 to the upper end of the die 34. Finally, the tablet 36 is removed by a scraper (scraper) 37, the lower punch 33 is returned to the center of the die 34, and the next drug powder 35 is put into the die 34. Thereafter, the same process is continuously performed.

In the tableting machine 31, when the powder 35 adheres (sticks) to the molding surface that is the tip of either of the upper and lower punches 32 and 33, the tablet 36 adheres to the upper and lower punches 32 and 33, and the tablet 36 Cannot be separated, and further processing cannot be performed. Therefore, in this test, the lifetime of the coating film was determined when the powder 35 adhered to the molding surface and the tablet 36 was not peeled off from the tip surface of either the upper punch 32 or the lower punch 33. . Furthermore, the tableting machine 31 used in this test has 50 sets in total consisting of upper and lower punches 32 and 33, and the coating life was evaluated in units of lots with 300,000 tablets as one lot. .

As shown in Table 1, in the case of １０B without any conventional coating, sticking occurred in 10 lots. However, V on the V coating ₆₀ C ₄₀ 杵 C coated with a coating extended its life to 30 lots. This is V ₆₀ C ₄₀ Since the hardness of the molding surface is increased by coating the coating, it is considered that the life is extended as a result of the increased wear resistance.

On the other hand, the film according to the present invention, that is, V film, V ₆₀ C ₄₀ V in the order of coating ₂₅ C ₇₅ 杵 A coated with a coating consisting of 寿命 A had a life span of 60 lots, 6 times that of 杵 B and twice that of 杵 C. This is because V coated on the outermost layer of 杵 A ₂₅ C ₇₅ V coated on the surface of 杵 B ₆₀ C ₄₀ V compared to the coating ₂₅ C ₇₅ Since the coefficient of friction of the coating is low, the drug powder is less likely to adhere to the surface of the upper and lower eyelids, and as a result of the improved releasability of the upper and lower eyelids 32 and 33 with respect to the tablet 36, the lifetime is considered to be extended.

From the above results, the V film, V, which is the film according to the present invention, ₆₀ C ₄₀ Coating and V ₂₅ C ₇₅ By covering the surfaces of the upper and lower punches 32 and 33 for the tableting machine 31 with the coating, the adhesion with the drug powder 35 is suppressed and the releasability from the tablet 36 is improved. As a result, the number of times of tableting can be increased. done.

Next, a vanadium-containing coating according to the present invention was coated on the drill surface made of high-speed tool steel (SKH51) by the same coating method as described above, and a cutting test by drilling was performed. The results are shown in Table 2.

Table 2 shows (1) the coating according to the present invention, that is, the V coating on the lowermost layer, ₄₀ C ₆₀ Coating, V ₁₅ C ₈₅ A drill (hereinafter referred to as “drill A”) in the order of the coating consisting of: (2) a drill without any coating (hereinafter referred to as “drill B”), and (3) a coating of TiN (titanium nitride). Drill (hereinafter referred to as drill C), (4) V coating on the bottom layer, V ₄₀ C ₆₀ The drill life (number of drilling holes) is shown when a cutting test is performed using a total of four types of drills (hereinafter referred to as drill D) coated with a coating. This cutting test was performed under the following conditions.
  ・ Used drill φ6mm × 115mmL
  ・ Drill rotation speed: 2122 rpm (40 m / min)
  ・ Drill feed amount 0.1mm / rev
  -Work material S50C material (hardness: 210HB, plate thickness: 19mm)
  ・ With or without grinding fluid (Dry)
In this cutting test, the drill life was determined based on the chip of the drill blade or the breakage of the drill.

As shown in Table 2, the drill B without any coating broke the drill in the processing of 10 holes or less and reached the life. On the other hand, the life of the drill C coated with a TiN film, which is a typical film conventionally used in cutting tools such as drills and end mills, has increased to 250 to 300 holes, and a hard film such as a TiN film is attached to the drill surface. The effect of the life improvement by this was confirmed. Furthermore, the V film is coated on the lowermost layer and then V ₄₀ C ₆₀ The service life of drill D coated with coating increased to 329-429 holes. This is because the V coated on the drill D ₄₀ C ₆₀ This is considered to be due to the fact that the coating is harder (higher surface hardness) than the TiN coating coated on drill C.

On the other hand, the film according to the present invention, that is, V film, V ₄₀ C ₆₀ V in the order of coating ₁₅ C ₈₅ The drill A coated with the coating has a life increased to 600 holes, and the life has been improved to twice that of the drill C and 1.4 to 1.8 times that of the drill D. This is because the V coated on the surface of the drill A ₄₀ C ₆₀ While the coating retains its hardness, V ₁₅ C ₈₅ This is considered to be the effect of increasing the chip dischargeability while reducing the wear of the film due to the excellent lubricity of the film.

From the above results, the V film, V, which is the film according to the present invention, ₄₀ C ₆₀ V on the coating ₁₅ C ₈₅ By coating the coating on the cutting tool (drill), it was possible to reduce the wear of the coating and improve the drill performance (life).

In Example 3, the case where the drill is coated with a coating such as a vanadium-containing coating according to the present invention has been described. However, the same effect can be obtained even when the cutting tool such as an end mill, broach, or hob is coated. Needless to say.

Claims (2)

A film coated on a base material made of an iron-based alloy, wherein the film is made of V _(1-X) C _X , and the X is a vanadium-containing film having an atomic% of more than 70 at% and not more than 95 at%. In addition, a composite coating is coated between the iron alloy base material and the vanadium-containing coating, and the composite coating is a V coating, V _(1-Y) C in order from the iron alloy base material. A vanadium-containing coating film characterized by being a coating film composed of a _Y coating film (where Y is 40 atomic% to 60 atomic% in atomic percent) . The mold or cutting tool coated with a vanadium-containing coating according to claim 1, wherein the iron alloy base material is a mold or a cutting tool.

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