JPS6363321B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an improved cutting tool for cutting non-metallic hard materials.

Technical background Non-metallic hard materials such as gypsum board, particle board, apitone wood, laminated wood, and reinforced plastic materials contain gypsum, asbestos, glass fiber, etc., or are impregnated with an adhesive to give them strength. It is made as hard as it is. Therefore, when using steel blades such as high-speed steel and alloy tool steel for cutting these materials, the wear is high and the lifespan is short, which increases tool costs and requires frequent replacement, which reduces work efficiency. I was getting used to it. Furthermore, the requirements for wear resistance are still not fully satisfied in WC--Co based sintered alloys. Furthermore, diamond compacts or
Although CBN has excellent wear resistance, it has a disadvantage in terms of price.

Purpose Therefore, the present invention has been made as a result of intensive research to solve the above-mentioned problems, and based on various experiments on adhesion between oxide ceramics and metals, has been developed to develop carbides and borons that have super wear resistance in oxide ceramics. We discovered a method of strongly adhering ceramics made by binding oxides or nitrides to Cu or Cu alloys, and created blades for non-metallic materials that strongly adhered to the base metal of the blade by brazing the Cu layer. This is what we are trying to provide.

The gist of the present invention is to use oxides such as Al ₂ O ₃ , ZrO ₂ , MgO, etc. as a matrix, and to use oxides such as TiC, TiB ₂ , Si ₃ N ₄ as a matrix.
By dispersing and strengthening carbides, borides, and nitrides such as carbides, borides, and nitrides, two layers are formed: an ultra-hard material layer that will become the cutting edge part, and an oxide-based layer that will serve as an adhesion mediating part of the same type as the oxide used as the matrix. This is a cutlery in which the Cu layer, which is formed by bonding the oxide-based ceramic layer of sintered ceramics with Cu or Cu alloy through an oxidation reaction, is bonded to the blade base metal by brazing.

Solution: Oxide ceramics such as Al ₂ O ₃ , ZrO ₂ ,
MgO, etc. as a matrix and carbides of ultra-hard substances such as TiC, WC, Mo ₂ C, VC, borides such as TiB ₂ , TaB ₂ , W ₂ B ₅ , nitrides such as Si ₃ N ₄ ,
Ceramics with dispersion reinforcement of TiN and BN, for example,
The hardness of ceramics such as Al ₂ O ₃ +TiC and Al ₂ O ₃ +TiB ₂ is higher than that of single oxide ceramics, e.g.
Because it has a higher hardness than Al ₂ O ₃ , it is suitable as a cutting tool for cutting difficult-to-cut non-metallic materials such as gypsum board and particle board, and is cheaper than diamond, borazone, etc. Due to the rapid development of ceramics, it is expected that they will become even easier to obtain. However, for example, Al ₂ O ₃ +
Superhard ceramics such as TiC, Al ₂ O ₃ + TiB ₂ , etc. have weak adhesive strength with Cu because Cu does not react easily even when heated to high temperatures. For this reason, even if the Cu and the blade base metal are brazed, the actual situation is that they peel off due to the cutting force applied to the blade, making it unusable. Therefore, in order to use ceramics, which have relatively good toughness and ultra-hardness, as the cutting edge material of cutting tools made of cutting materials, it is necessary to avoid direct adhesion between the metal that can be brazed and the ultra-hard ceramics. We came up with the idea of using ceramics as an intermediary with a material that can be bonded to metal due to its leakage properties.

The inventors were able to select oxide ceramics as the intermediary material based on currently available bonding technology. That is, Cu as a metal for Al ₂ O ₃
It was also confirmed through experiments that when a Cu alloy is heated to a high temperature, Cu turns into Cu ₂ O, which easily invades Al ₂ O ₃ and strongly adheres to it. Therefore, it is necessary to prevent the aforementioned carbides, borides, and nitrides from being mixed into the oxide-based ceramics, and even if they are unavoidably mixed, it is absolutely necessary that they be as small as possible.
Therefore, for example, the Al ₂ O ₃ + TiC layer and the adhesion mediating material
As an example of the process of manufacturing two-layer ceramics with _three Al ₂ O layers, 99.99% purity is added to the bottom layer of the mold.
Fine powder of 0.1μm to several μm with an average particle size of 0.5μm and a thickness of 0.4mm
The first layer is packed in layers, and each layer in which the mixing ratio of the ultra-hard material TiC is successively increased is laminated on top of the first layer. In other words, compared to the same Al ₂ O ₃ fine powder, TiC
For example, fine powder of 0.1 μm to several μm and an average particle size of 0.5 μm is
Thickness of the mixture mixed with weight% and distributed evenly
A second layer of 0.5mm layered powder, on top of which a 0.5mm thick third layer of powder mixed with the same material at a mixing ratio of 10% by weight, and on top of that a mixed powder of 20% by weight of the same material. A fourth layer with a thickness of 0.6 mm is made of mixed powder, and on top of that, a fifth layer with a thickness of 1.0 mm is made of a mixed powder with a mixing ratio of 30% by weight to obtain the hardness and wear resistance suitable for the blade material.
A layer is formed and sintered by a hot press method in which the material is heated to about 1500° C. and high pressure of about 300 kg/cm ² is applied for several tens of minutes, or by a hip method.

The ultra-hard ceramics produced in this way are dispersed and strengthened using the oxide Al ₂ O ₃ as a matrix and the ultra-hard TiC is mixed therein. ) side becomes the adhesive mediating layer. On top of the Al ₂ O ₃ layer of this ceramic, a Cu or Cu alloy such as a tough pitch copper plate with a thickness of 0.5
A plate material of ~3 mm is placed on the plate and held in an oxidizing atmosphere (in this example, air) at a temperature in the range of 1080°C to 1145°C for 5 to 20 minutes to bond the ultra-hard ceramic and Cu.
The shear fracture strength when bonded in this temperature range is
It showed a high value of 5.7Kg/ ^mm2 . Next, the ultra-hard ceramic material with Cu adhered to it in this way is then bonded to the iron base of the blade using the usual method such as silver soldering.
It brazes Cu and iron.

Experimental example using this cutter Grooving cutter...2 blades Outer diameter...200φmm Cutting blade width...20mm Number of revolutions...5000r.pm Feed rate...2m/min Depth of cut...15mm Work material...Particle board #200 Cutting direction...Upward cutting Under these conditions, even when the cutting length was 100 m or more, no peeling or falling off phenomena were observed, and it was confirmed that the adhesive had sufficient adhesive strength for practical use.

In the above explanation, the subject matter is ceramics in which two phases are formed of the same type of oxide and a super-hard material that uses one type of oxide as a matrix and disperses and strengthens one type of ultra-hard material, but is not limited to this. . for example
An ultra-hard material that uses a powder mixture of two types of oxides, Al ₂ O ₃ and ZrO ₂ as a matrix, and disperses and strengthens carbide TiC.
Two-layer ceramics with sintered oxide layers of Al ₂ O ₃ and ZrO ₂ , or two-layer ceramics with only Al ₂ O ₃ as an oxide layer without changing the ultra-hard material system. More than one type of oxide, two or more types of carbide,
Ceramics can be selected in consideration of their characteristics, such as a combination of borides and nitrides, or a combination of two types and one type. Furthermore, when two or more types are mixed, the ratio is selected depending on the characteristics, and it is most preferable that the oxide used as the matrix phase and the oxide used as an adhesion mediator are the same type, but if the coefficient of thermal expansion or chemical properties are taken into consideration, The purpose can be achieved if the main oxides are the same or the ratios are not very different. If the part that becomes the blade is a layer with ultra-high hardness and the other side is an oxide layer that can be bonded to Cu or Cu alloy by oxidation reaction, the layer in between will be hard unless thermal stress occurs due to heating. The ratio of components or, in the extreme, the mixing of other substances can be tolerated.

Note that it is also possible to replace Cu or a Cu alloy with a substance having the same effect.

Effects As described in detail above, the present invention is a ceramic material formed by sintering into two layers: an ultra-hard layer in which an oxide is used as a matrix, and a super-hard layer in which carbides, borides, and nitrides are dispersed and strengthened, and an oxide layer of the same type. Since the Cu material is bonded to the metal and then brazed to the blade metal, the oxide layer acts as an adhesion mediator to the metal, making it possible to firmly bond the ultra-hard ceramic material, resulting in super wear resistance. It is possible to obtain a long-life cutting tool for non-metallic hard materials that requires high-quality cutting, and it is economical and provides a well-finished cutting surface without hindering workability due to replacement etc., improving the commercial value of the product. It has the characteristics of being able to

[Brief explanation of drawings]

The drawing is a diagram showing an example of the constituent layers of the blade portion.

Claims (1)

[Claims] 1 _TiC , _{TiB 2 ,}
An ultra-hard material layer formed by dispersion-strengthening one or more of carbides, borides, and nitrides such as Si ₃ N ₄ to form the cutting edge, and an oxide of the same type or almost the same type as the matrix oxide. The oxide-based ceramic layer of the ceramic is formed by sintering two oxide-based layers that serve as adhesion intermediaries, and the Cu layer formed by adhering Cu or a Cu alloy through an oxidation reaction is bonded by brazing. A cutlery whose blade material is made of ceramics consisting of multiple layers of an ultra-hard substance layer and an oxide layer, characterized in that the blade is bonded to the blade base metal.