JP3009177B2 - Coated ceramic sintered body with excellent adhesion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a non-oxide ceramic sintered body containing a non-oxide such as silicon nitride, sialon, silicon carbide and aluminum nitride as a main component. A coated ceramic sintered body that forms a coating with excellent adhesion and abrasion resistance on the surface of a base material and can be applied to various materials including tool materials such as cutting tools or wear-resistant tools It is.

(Prior Art) Conventionally, attempts have been made to form a coating on the surface of a ceramic sintered body and apply it as a decorative material or a cutting tool material. A typical example is Japanese Patent Publication No. 61-14942. JP-A-59-232985 and JP-A-61-191584.

(Problems to be Solved by the Invention) Japanese Patent Application Laid-Open No. 61-14942 discloses that a surface of an alumina ceramic sintered body or a zirconia ceramic sintered body is coated with Ti.
Metal or TiC, ZrO ₂ ceramic lower layer and TiN, ZrN
And a multi-layer decorative coating formed by forming an outermost layer of a decorative color. This publication discloses a ceramic sintering method that enhances the bonding strength with the substrate, that the thickness is sufficient to smooth the irregularities on the surface of the substrate, and that it has hardness and decorative colors. This is an excellent invention formed on a body substrate and completed as a decorative multilayer coating. However, the multilayer coating disclosed in the publication is based on an oxide ceramic sintered body containing aluminum oxide or zirconium oxide as a main component, and has a coating composition suitable for decoration. However, when this is applied as a tool material, the adhesion strength between the base material and the coating is poor,
As a result, there is a problem that peeling of the coating occurs.

JP-A-59-232985 discloses α-sialon and β-sialon.
One of the carbides, nitrides, carbonitrides, carbonates and carbonitrides of Ti, Zr, Hf is deposited on the surface of the base material of the non-oxide ceramic sintered body mainly composed of sialon. Layer or 2
A coated ceramic sintered body formed by forming a coating composed of at least two or more layers is disclosed. Also, JP-A-61-191584
Japanese Patent Application Laid-Open Publication No. 2000-209,199 discloses that one surface of a substrate of a non-oxide ceramic sintered body containing silicon nitride as a main component is a compound of Ti and one or more non-metallic elements selected from C, N, and O. Alternatively, a coated ceramic sintered body in which one or two or more coatings are coated is disclosed. Both of these publications have disclosed an excellent attempt to improve wear resistance by forming a high-hardness coating on the surface of a non-oxide ceramic sintered body containing sialon or silicon nitride as a main component. The invention has been disclosed.

However, the coated ceramics sintered bodies disclosed in both of these publications have extremely poor adhesion between the substrate and the coating because silicon nitride itself, which is a main component of the substrate, is a compound having an extremely strong covalent bond, As a result, there is a problem that the coating is easily peeled off and the wear resistance is not improved to a satisfactory level.

The present invention has solved the above-mentioned problems, specifically, by interposing a metal inner layer between a base material of a non-oxide ceramic sintered body and an outer layer of a hard metal compound. ,
It is an object of the present invention to provide a coated ceramic sintered body having improved adhesion between a substrate and a coating, peeling resistance, plastic deformation resistance, and welding resistance of the coating.

(Means for Solving the Problems) Compared with other tool materials, the present inventors have found that a non-oxide ceramic sintered body, particularly a silicon nitride ceramic sintered body, has an affinity for an iron based material. As the ratio tends to be high, as a countermeasure, improve the wear resistance by forming a hard ceramic film with low affinity with iron-based materials on the surface of the silicon nitride-based ceramic sintered body. In the course of studying this, Ti, Z
When the active metal of r, Hf is coated, the adhesion between the substrate and the active metal is remarkably improved, and Ti, Zr,
The inventors have found that the formation of a ceramic film such as a carbide or nitride of Hf significantly improves the adhesion strength between the active metal and the ceramic film, thereby completing the present invention.

That is, the coated ceramic sintered body having excellent adhesion of the present invention is a non-oxide ceramic sintered body containing at least one of silicon nitride, sialon, and silicon carbide as a main component. A coated ceramic sintered body having an inner layer and an outer layer formed on at least one surface, wherein the inner layer is a single layer or a multilayer of at least one of Ti, Zr, Hf metals and their mutual alloys. , The outer layer is Ti, Z
It is composed of at least one single layer or multiple layers of carbide, nitride, carbonate, nitride oxide, aluminum oxide and their mutual solid solution of r and Hf, and the total thickness of the inner layer and the outer layer is 3 μm. It is characterized by the following.

The base material of the coated ceramic sintered body having excellent adhesion according to the present invention is a sintered body containing at least one of silicon nitride, sialon, and silicon carbide as a main component, and the remaining part is For example, aluminum oxide,
Aluminum nitride, silicon oxide, magnesium oxide, calcium oxide, oxides of iron group metals, oxides of rare earth metals, boron, carbon, boron carbide, boron oxide, boron nitride, carbides of group 4a, 5a, and 6a metals in the periodic table , Nitrides, borides, oxides and their mutual solid solutions, silicon nitride whiskers, at least one of silicon nitride whiskers, or those containing a small amount of iron group metal mixed in from the manufacturing process. Specifically, for example, Si ₃ N ₄ -AlN
Based sintered body, Si ₃ N ₄ −Al ₂ O ₃ based sintered body, Si ₃ N ₄ −SiC based sintered body,
SiC-B ₄ C-based sintered body, can be cited _{Si 3 N 4 -Al 2 O 3} -ZrO 2 sintered body.

The inner layer coated on the surface of the base material is made of at least one active metal or active alloy among metals of Ti, Zr, Hf and their mutual alloys. Other trace metals and alloys such as Cu, Ni, Co, A
Even if g and the like are mixed, it hardly affects the effect of the adhesion, and can be sufficiently used as the inner layer. The thickness of the inner layer varies depending on the application.For example, when the inner layer is used as a tool material such as a cutting tool or a wear-resistant tool, the thickness of the inner layer may be 1.0 due to plastic deformation resistance and peeling resistance.
The thickness is preferably 0.1 μm or less, more preferably 0.1 to 0.5 μm in consideration of the strength of adhesion between the substrate and the inner layer.
Also, when using decorative materials or functional uses that are not used in very harsh conditions, the effect of the thickness of the inner layer is less of a problem.

The outer layer coated on the surface of the inner layer is, for example, TiC, ZrC, HfC, TiN, ZrN, Ti (C, O), Zr (C, O), Ti (N,
O), Zr (N, O), (Ti, Zr) C, (Ti, Zr) (C, O), (Ti, Z
r) (N, O), Ti (C, N, O), (Ti, Zr) (C, N, O), Al ₂ O _{3 and the} like. This outer layer may have a non-stoichiometric composition, and its thickness differs depending on the application like the inner layer, and when used as a tool material, it is particularly 2.0 μm or less from the peeling resistance and chipping resistance. The thickness is more preferably 0.5 to 1.5 μm in consideration of abrasion resistance against clearance wear.

When the coated ceramic sintered body having excellent adhesion of the present invention is used as a decorative member, a corrosion-resistant member, or a tool member, the adhesion of the coating is not so important, and the inner layer and The total thickness of the outer layer and the outer layer is not particularly limited, and may be, for example, a thickness of 20 μm or less. However, when used as a tool material, when the total thickness of the inner layer and the outer layer exceeds 3 μm, The total thickness of the inner layer and the outer layer is preferably 3 μm or less, since the peeling or chipping in the coating is likely to occur, and the chipping or defect propagates to the base material to shorten the life. , More preferably 2 μm or less.

When producing a coated ceramic sintered body having excellent adhesion according to the present invention, the conventional non-oxide ceramic sintered body is in a state of a polished surface, or a surface state after sintering or heat treatment, and then, Conventionally, the inner layer is formed on the surface by a physical vapor deposition method (PVD method) using ion plating, sputtering, laser or the like, and then the outer layer is formed by the PVD method, or the outer layer is formed by a conventional method. It can be performed by a known chemical vapor deposition method (CVD method) or a plasma CVD method.

At this time, depending on the manufacturing conditions, particularly the processing temperature for forming the outer layer, mutual reaction between the substrate and the inner layer and between the inner layer and the outer layer may occur. In this case, a nonmetallic element is invaded in the inner layer adjacent to the outer layer or the inner layer adjacent to the base material. For example, the base material is a base material containing silicon nitride or sialon as a main component, the inner layer is Ti, and the outer layer is TiN.
In the case of, an extremely thin layer of TiN _1-X (1>X>)
O), a Ti layer, and a TiN layer are sequentially formed. In order to suppress the invasion of the non-metallic element into the inner layer as much as possible, it is preferable to lower the processing temperature of the inner layer and the outer layer.

(Function) The coated ceramic sintered body of the present invention having excellent adhesion has an inner layer that acts as a mediator of the adhesion between the base material and the outer layer. It has a buffering effect and a heat dissipation effect on heat,
The outer layer acts to enhance the wear resistance.

(Example) A commercially available Si ₃ N ₄ -5Al ₂ O ₃ -5Y ₂ O ₃ ceramic sintered body was used as a substrate, and this substrate was placed in a hollow hot cathode type ion plating reaction vessel. The substrate was coated with titanium metal under the conditions of an atmosphere in the reaction vessel, an electron beam at a pressure of 10 ⁻⁴ Torr, 40 v / 500 A, and a substrate temperature of 200 ° C. (first treatment), and then reaction vessel atmosphere _{50vol% Ar-500vol% N 2} , pressure 10 ^-3 Torr, a substrate temperature of 500
C. (secondary treatment) to obtain the product 1 of the present invention.

As a comparison, a comparative product 1 was obtained by performing only the second processing without performing the above-described first processing, and performing the other processing under the same conditions. Further, only the above-described first treatment was performed, and the second treatment was not performed.

When the product 1 of the present invention and the comparative products 1 and 2 thus obtained were examined by a scanning electron microscope, a scanning Auger electron microscope and X-ray analysis, the product 1 of the present invention was found to have an inner layer of 0.3 μm thick Ti, an outer layer of
It is made of 1.0 μm thick TiN, and the comparative product 1 is 2.5 μm
Comparable product 2 consists of only a TiN layer with a thickness of 3.0 μm.
It consisted of layers only.

These inventive product 1 and comparative products 1 and 2 were subjected to a cutting test under the following turning test conditions, using the above-mentioned substrate consisting of only the base material as comparative product 3, and the average flank of each sample during the cutting time. The amount of wear was determined, and the results are shown in Table 1.

Turning test conditions Work material Cast iron (FC35) Cutting speed 150m / min ~ 900m / min Depth of cut 1.0mm Feed 0.3mm / rev Cutting time 10min Tool shape SNGN120408 Pre-honing 0.15 × -25mm Wet cutting (Effect of the Invention) The coated ceramic sintered body of the present invention having excellent adhesiveness is less likely to peel the coating film than the conventional comparative product, and also causes micro chipping of the substrate accompanying the peeling of the coating film. It is difficult to improve the wear resistance as a result, and it is difficult to reduce the surface roughness of the mating material such as a work material, especially when a ceramic sintered body is used as a cutting tool, In the cutting speed range of 150 to 300 m / min, which belongs to the low cutting speed range, there is an effect that the wear resistance is remarkably superior to the conventional comparative product.

Further, the coated ceramic sintered body having excellent adhesion of the present invention also has a use management effect of identifying before and after use of a tool member by differentiating the color of the base material and the color of the coating film, particularly the outer layer. In addition to this tool member,
It is an industrially useful material that can also be used as a decorative material or a corrosion resistant material.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-96084 (JP, A) JP-A-59-159982 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 41/80-41/91

Claims (3)

(57) [Claims] An inner layer and an outer layer are formed on at least one surface of a substrate of a non-oxide ceramic sintered body containing at least one of silicon nitride, sialon and silicon carbide as a main component. Wherein the inner layer is a single or multiple layer of at least one of Ti, Zr, Hf metals and their alloys, and the outer layer is T
i, Zr, a single layer or a multilayer of at least one of carbides, nitrides, carbonates, nitrides, aluminum oxides and mutual solid solutions of Hf, and a total of the inner layer and the outer layer A coated ceramic sintered body having excellent adhesion, having a thickness of 3 μm or less. 2. A coated ceramic sintered body having excellent adhesion according to claim 1, wherein said inner layer has a thickness of 0.5 μm or less. 3. The coated ceramic sintered body having excellent adhesion according to claim 1, wherein said outer layer has a thickness of 1.5 μm or less.