JP2002038255A - Abrasion resistant lubricating-film and coated member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasion resistant lubricating-film consisting of solid lubricant and hard coating, which can prolong the service life of sliding parts like tools such as a tip, a drill, and a die, and bearings, even in a hard service condition, by giving the lubricating-film a structure in which the solid lubricant is supplied to a surface of the hard coating over a long period. SOLUTION: The lubricating-film is characterized by that the solid lubricant is filled in concavity provided on the surface of the hard coating on a base material, which has diameter of dozens μm, depth ratio of 0.3 or deeper against the total film thickness, and area ratio of 0.05-0.4 against the total coating area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tip, a drill,
Cutting tools such as end mills, dies, wear-resistant tools such as cutting blades, and wear-resistant lubricating films used for sliding parts such as liners and bearing bushes. Abrasion-resistant lubrication with extended lubrication, welding resistance, and oxidation resistance as well as wear resistance, as well as improved wear resistance by filling solid lubricant into the finely dispersed fine recesses to form an embedded structure. It relates to a membrane and a covering member.

[0002]

_2. Description of the Related Art TiN, TiCN, TiC, Al ₂ O ₃ ,
Hard coatings such as (TiAl) N are used for cutting tools, wear-resistant tool parts and sliding parts, and contribute to prolonging the service life. However, depending on the work material and processing conditions or the mating material and sliding conditions, film peeling and chipping of the base material due to frictional stress, oxidative deterioration of the film due to heat generation, oxidative wear, thermal deterioration of the base material, deformation, etc. However, there is a problem that it is difficult to extend the service life.

[0003] Therefore, a CVD composite film in which sulfides are dispersed in these hard films, and molybdenum disulfide (MoS ₂ ), tungsten disulfide (WS ₂ ), graphite,
A number of coated tools or parts have been proposed that extend the life by imparting lubricity to a hard coating, such as a PVD multilayer film coated with diamond-like carbon (DLC) or the like. Representative examples of the prior art relating to the lubricating composite film include Japanese Patent Publication No. 1-26802 and Japanese Patent Application Laid-Open No. 2-22.
No. 1714 and Japanese Patent Application Laid-Open No. 2000-001768.

[0004]

Among the prior arts relating to the lubricating composite film, Japanese Patent Publication No. 1-26802 discloses that 4a, 5a and 4a, 5a and 4a are formed on the surface of a tool component made of a cemented carbide, cermet or iron-based material. A coated tool part in which a composite composition comprising a hard phase composed of a carbide, nitride, boride, aluminum oxide or the like of a Group 6a metal and a metal sulfide phase (particularly titanium sulfide) is used as an inner layer, and the outermost layer is a hard phase is provided. Has been described. The coated tool described in the publication aims to extend the tool life by reducing friction, welding, wear and the like by the lubricating action of the contained metal sulfide. However, metal sulfides are low in hardness, brittle and unstable, and conversely promote wear, and the film is mechanically chipped or peeled, oxidized or absorbed by moisture. There is a problem that it is less effective

Japanese Patent Application Laid-Open No. 2-221714 discloses that a sliding surface of a bearing is coated with a laminated film of TiC and a soft metal such as gold, silver or lead or a layered solid lubricant such as MoS ₂ or WS _2. Described solid lubricated bearings. Also,
JP 2000001768 discloses periodic tables 4, 5,
The base layer of a high hardness coating composed of a Group 6 metal element and one or more elements selected from Al, Si, B, and C, and one or more elements selected from B, C, N, and O, and mainly molybdenum disulfide In the accumulated phase coating having a surface layer as a component, the surface layer contains at least one of Group 4, 5, and 6 metal elements in an amount of 0.5 at% to 10 at%.
A composite wear resistant hard coating with solid lubricity containing at% is described.

The lubricating coatings described in both publications are MoS
_Although MoS ₂ is a soft film that wears or peels off from the base film, it has little effect on extending the life of the tool under cutting or severe sliding conditions. There is a problem to say.

[0007]

The present inventors have studied a wear-resistant lubricating film having both wear resistance and lubricity for many years. When the solid lubricating film is coated, the solid lubricant in the convex portion is easily worn out in the initial stage of friction with the work material, but when the hard coating is exposed, the hard coating in the convex portion is held in the concave portion while maintaining wear resistance. Since the solid lubricant is gradually supplied to the hard coating surface, the friction and wear are significantly suppressed, and the low friction and wear are maintained until the solid lubricant is consumed. As for the shape, if there are minute and numerous circular concave parts on a smooth surface, the wear resistance and lubricity are well balanced, and the lubrication and welding resistance can be maintained for a long time even under severe processing or sliding conditions, and the life is long Can be extended significantly Te which has led to the completion of the present invention.

The wear-resistant lubricating film of the present invention has a thickness of 1 to 20 μm.
In a hard coating consisting of a single layer or multiple layers of thickness, the depth ratio of the hard coating surface to the total thickness is 0.3 or more, the diameter is 1 to 100 μm, and the area ratio of the opening surface to the surface area of the hard coating is 0.05. .. 0.40, which are characterized by being filled with a solid lubricant.

The base material for coating the wear-resistant lubricating film of the present invention is, specifically, a WC-Co type, WC- (WTiTa)
C-Co based, WC-TaC-Co based hard metal, TiC-Mo-Ni based, TiCN-WC-TaC-
Cermet such as Ni-Co-based, Al ₂ O ₃ system, Al ₂ O ₃
-Ceramics such as TiC and Si ₃ N ₄ and cubic boron nitride (cBN) as main components, and metal Co, Al or ceramic components such as TiN, Al ₂ O ₃ , AlN and TiB ₂ as a binder phase. Cubic boron nitride sintered body,
High-speed steel and tool steel can be mentioned.

The hard coating in the wear-resistant lubricating film of the present invention is, specifically, TiC, TiN, Ti (CN), Ti
(CNO), ZrN, HfN, VN, Al ₂ O ₃ , ZrO
₂ , (TiAl) N, (TiAl) (CNO), elements of groups 4a, 5a and 6a of the periodic table, aluminum, carbides, nitrides, oxides of silicon, and mutual solid solutions thereof. When the thickness of the hard coating is 1 μm or less, the effect of improving the wear resistance is small, and when the thickness exceeds 20 μm, abnormal wear due to film peeling or breakage due to a decrease in strength is liable to be caused. When the outermost layer of the hard coating is at least one of titanium carbide, nitride, carbonitride, composite nitride of titanium and aluminum, and composite carbonitride by PVD, the surface of the film is subjected to post-treatment. This is preferable because it is easy to form an uneven portion on the surface, and has a smooth surface and excellent wear resistance.

The solid lubricant in the wear-resistant lubricating film of the present invention is, specifically, molybdenum disulfide, tungsten disulfide, graphite, graphite fluoride, lead monoxide, boron nitride, calcium fluoride, barium fluoride. , Fluorine resin, diamond-like carbon, and the like.

The recesses on the surface of the hard coating in the wear-resistant lubricating film of the present invention have a depth of at least 0.3 in a thickness ratio with respect to the total thickness of the hard coating, and are less than 0.3 in a thickness ratio. At a depth of, the solid lubricant is not supplied along with the wear of the hard coating, and the life is shortened. When the diameter of the concave portion is less than 1 μm, it is difficult to fill the solid lubricant, and the distance of the concave portion is relatively short, so that the strength of the hard coating is reduced. The outflow due to the friction of the oil becomes severe, and the life is shortened. Further, when the area ratio of the concave portion to the surface area of the hard coating is less than 0.05, the effect of reducing friction and wear is small because the solid lubricant is insufficient, and when it exceeds 0.40, the ratio of the hard coating relatively increases. , The wear resistance is reduced.

The solid lubricant in the abrasion-resistant lubricating film of the present invention is filled in the recesses on the hard film, and the entire surface of the hard film has a single-layer or multilayer film having a thickness of 10 μm or less. Is preferable because sufficient lubricity can be secured at the beginning of friction.

The method of forming a wear-resistant lubricating film according to the present invention is, as a method of forming a concave portion on a hard film, specifically, a droplet generated during vapor deposition in an arc ion plate device or a foreign material dispersed in a coating. Chemical removal of particles,
Laser beam irradiation and the like can be mentioned. In addition, as a method of filling the solid lubricant into the concave portion on the hard coating, specifically, mechanical rubbing of various solid lubricant powder, application of paste and vacuum deposition of solid lubricant, sputter deposition,
Reactive sputtering and CVD coating can be mentioned. Among these methods, the formation of a concave portion using droplets and the formation of a lubricating film by sputter deposition using a solid lubricant as a target are preferable because the production is easy and the size and amount of the concave portion can be controlled.

[0015]

In the wear-resistant lubricating film of the present invention, the hard film coated on the base material functions to improve the wear resistance, and the projections formed on the hard film surface function to hold the solid lubricant. The solid lubricant filled in the concave portion is gradually supplied to the friction surface on the hard coating, and acts to reduce friction and wear.

[0016]

Example 1 As a substrate, a commercially available solid drill made of cemented carbide (φ8.0 mm, composition: WC-10 wt%)
Co, hardness: HRA = 91.5) was prepared, and an arc ion plating apparatus capable of mounting a four-electrode target and spraying powder on the surface of a processed material was used as a hard coating apparatus. First, a base material drill is inserted into the apparatus to make a vacuum of about 1 × 10 ⁻³ Pa, and then heated to 773 K and A
The inside of the apparatus was adjusted to about 0.1 Pa while introducing r gas, and -6
The drill surface was sufficiently ion-cleaned by Ar ion reverse sputtering by applying a bias voltage of 00 V for 10 minutes and then degassed. Next, the coating process was sequentially performed under the coating conditions (target type, gas component and flow rate, bias voltage, processing time) shown in Table 1, thereby obtaining coated drill materials A to E.

[0017]

[Table 1] * Note) IP: Ion plating (reactive deposition) PD: Particle deposition (lumped particle deposition)

Next, the coated drilling materials A to E were subjected to the pretreatments shown in Table 2. The cutting edge of the coated drill after the pretreatment was observed with a scanning electron microscope, and the average diameter of the concave portion formed on the coating surface and the area ratio of the concave portion to the entire surface were determined. The results are shown in Table 2. Then, these pretreated coated drilling materials were charged into a magnetron sputtering apparatus, and subjected to a coating treatment of a solid lubricant under a combination of a target, a gas component and a pressure, a bias voltage, and a processing time described in Table 2, Drills coated with a wear-resistant lubricating film of inventive products 1 to 8 and comparative products 1 to 5 were obtained. For these, the results of observation and measurement of the film configuration (component, film thickness) in the cross-sectional structure of the cutting edge, the depth ratio of the concave portion to the film thickness of the hard coating, and the depth at which the solid lubricant is filled in the concave portion are shown. 3 is shown.

[0019]

[Table 2] * Note) Immersion condition: 10% HCl in 10 minutes Electrolysis condition: 2.5V × 0.05A / cm ² × 2.0
min

[0020]

[Table 3]

Using the obtained drills of the present invention 1 to 8 and comparative products 1 to 5 coated with a wear-resistant lubricating film, a work material: S45
C, Cutting peripheral speed: 80m / min, hole depth: 40m
m, drilling was continuously performed under dry processing conditions. Table 4 shows the number of holes that can be machined until a sharp increase in torque occurs due to occurrence of chipping, breakage or clogging of chips. When the machining was normal up to 400 holes, the average flank wear of the cutting edge was also described.

[0022]

[Table 4]

[0023]

Example 2 Commercially available mold steel materials (SKD11, HRC =
60), cutting and polishing 6 × 10 × 16m
m was made and one side was wrapped. Then, using the same method and conditions as in Example 1, products 9 to 13 of the present invention and comparative products 6 to 8 shown in Table 5 were obtained. Using a ring-on-block type friction and wear tester (LFW-1 method), the lap-finished surface of the abrasion-resistant lubricating film-coated block thus obtained is mated with a standard ring of SAE4620, load: 50 kg, friction speed : 30 m / min, Atmosphere: A friction test was performed under dry conditions in the air. Friction coefficient is 0.3
Table 5 also shows the friction time (but stopped at a maximum of 100 hours) and the abrasion width until it rapidly increased beyond the limit.

[0024]

[Table 5]

[0025]

Embodiment 3 Cemented carbide materials for wear-resistant tools (JIS V3
0), the entire surface is rough- and finish-ground with 140 # and 800 # diamond grindstones to produce punches for punching, and then the same as Example 2 of the present invention and Comparative Example 1 According to the method and the conditions, a punch coated with a wear-resistant lubricating film of the present invention 14 and the comparative product 9 were obtained. Using these, the thickness:
A 0.6 mm zinc steel plate was punched out, and the number of shots until a defective product was generated due to burrs was measured. As a result, the product 14 of the present invention has about 810,000 shots,
Comparative product 9 had about 430,000 shots.

[0026]

EFFECTS OF THE INVENTION Compared to the conventional wear-resistant lubricating film having a laminated structure in which a solid lubricating film is coated on a hard coating, there is no sharp decrease in lubricity due to the abrasion of the solid lubricant. Can be held for a long time, and the life of tools and sliding parts can be extended.

Continued on the front page F term (reference) 3C037 CC01 CC02 CC04 CC08 CC09 CC10 CC11 3C046 FF01 FF02 FF03 FF04 FF05 FF11 FF16 FF19 FF25 4K029 AA02 AA04 BA54 BA55 BA58 BA60 BB02 BC02 BD05 EA01

Claims (6)

[Claims] 1. A hard coating consisting of a single layer or a multilayer having a thickness of 1 to 20 μm, wherein the hard coating surface has a depth ratio to the film thickness of 0.3 or more, a diameter of 1 to 100 μm, and an opening relative to the surface area of the hard coating. The area ratio of the surface is 0.05 to
A wear-resistant lubricating film characterized by being dotted with recesses of 0.40 and filled with a solid lubricant. 2. The hard coating is composed of 4a, 5a of the periodic table.
2. The wear-resistant lubricating film according to claim 1, wherein the lubricating film is at least one selected from the group consisting of elements a and 6a, aluminum, silicon carbide, nitride, oxide and mutual solid solutions thereof. 3. The hard coating, wherein at least the outermost layer has P
2. The anti-reflection film according to claim 1, comprising at least one of titanium carbide, nitride, carbonitride, composite nitride of titanium and aluminum, and composite carbonitride formed by a VD method. Abrasive lubricating film. 4. The solid lubricant comprises molybdenum disulfide,
3. It is one or more of tungsten disulfide, graphite, graphite fluoride, lead monoxide, boron nitride, calcium fluoride, barium fluoride, fluororesin, and diamond-like carbon. 3. A wear-resistant lubricating film according to 3. 5. The hard coating surface including the concave portion,
5. The wear-resistant lubricating film according to claim 1, wherein the solid lubricant film having a thickness of 10 μm or less is coated with the solid lubricant film. 6. A cemented carbide, cermet, ceramic,
A cubic boron nitride sintered body, a film formed on a substrate made of at least one of hard steel,
A wear-resistant lubricating film-coated member according to 2, 3, 4 or 5.