JPS6020457B2 - High-toughness boron nitride-based ultra-high pressure sintered material for cutting and wear-resistant tools - Google Patents

Description

Detailed Description of the Invention This invention has particularly excellent grain hardness and wear resistance, as well as high hardness, excellent heat resistance and high temperature strength, and is suitable for use in high-speed steel and other steels that require these properties. , Ni group or Co
The present invention relates to a nitride-base ultra-high-pressure bonding material that can be used as a cutting tool for work materials such as base super alloys, and as wear-resistant tools for bearings, wire drawing dies, and the like.

In recent years, cubic nitride-based ultra-high pressure aged materials (hereinafter referred to as CBN-based sintered materials), which have extremely superior wear resistance compared to tungsten carbide-based sintered materials, have been used for cutting tools and wear-resistant tools. It is proposed to do so. This CB
N-based materials can be roughly divided into two types depending on the binder phase of the CBN particles that form the dispersed phase. One of these is one in which the binder phase is composed of iron group metals or metals containing N as the main component. Yes, the other is titanium nitride, titanium carbide,
The binder phase is made of a ceramic compound whose main component is aluminum nitride or aluminum oxide.

However, in the former, as the binder phase is metal as mentioned above, it easily softens at high temperatures, and therefore, when used as a cutting tool, for example, under caustic cutting conditions that generate a large amount of heat. Due to lack of wear resistance, sufficient cutting performance cannot be expected, and under conditions with little heat generation,
In other words, it can only be used under light load conditions. In addition, in the latter case, as the binder phase is composed of a ceramic compound as mentioned above, it has excellent heat resistance and abrasion resistance, but on the other hand, it cannot avoid the lack of rice grain properties. For example, chipping and breakage are likely to occur under cutting conditions in which a large impact force is applied to the cutting edge, such as when milling high-speed steel. Also,
In order to solve the problems of the above two conventional CBN-based materials, a CBN-based sintered material in which the binder phase was composed of a metal and a ceramic compound was also proposed.
This CBN-based condensed material also does not show sufficiently satisfactory quality, and similarly, when used as a cutting tool under cutting conditions where a large impact force is applied to the cutting edge, such as when milling high-speed steel, the cutting edge will break. It is easy to do.

This was revealed through detailed observation using a scanning electron microscope of the boundary between the CBN particles and the binder phase (metal/ceramic compound) in the above CBN-based sintering material. Sometimes, minute unbonded parts (voids) are formed at the boundary part due to the binder phase not being sufficiently wrapped around the minute recesses on the surface of the CBN particles, and furthermore, the bonding phase between the CBN particles and the binder phase is The adhesion of CBN varies depending on the constituent components of the binder phase, but it is particularly low in the case of carbide ceramics.
It is understood that this is caused by the formation of regions with weak bonding strength between the particles and the binder phase. Therefore, from the above-mentioned viewpoint, the inventors of the present invention aimed to obtain a CBN-based scale material that has particularly excellent toughness and wear resistance. Ti as reinforcing metal: 4 to 25% by weight, Ti nitride, carbide,
One or more of carbonitrides and shelved substances:
5 to 40% by weight, with the remainder being CBN (cubic nitride) and unavoidable impurities, and CBN occupies 40 to 90% by volume, and the bond-strengthening metal contains CBN. Assuming that the pongee weave is surrounded by an average layer thickness of 0.1 to IA, Ti as a bond-strengthening metal surrounding the CBN particles constituting the dispersed phase has good wettability with the CBN particles, and It reacts with impurities such as oxygen, water, oxides, etc. that adhere to the particle surface, removes them, and cleans them. Furthermore, when preparing the raw material, electroless coating method or chemical vapor deposition method (CVD method) is applied to the CBN particle surface in advance. ), physical vapor deposition method (PVD method), and plasma chemical vapor deposition method (PCVD method) to make the coating strong and dense, so that end bonds ( On the other hand, there are no Ti nitrides (hereinafter referred to as TIN), carbides (hereinafter referred to as TIC), carbonitrides (hereinafter referred to as TICN), and shelving (hereinafter referred to as TICN) of Ti that constitute the binder phase.
(Hereafter referred to as TiB) is in a state of mutual diffusion in the surface layer, so the CBN particles and the binder phase are TiB.
As a result, the material has extremely high ballability, and is not only ensured by the excellent wear resistance and high hardness of the CBN particles and the Ti compound, but also by the Ti compound. The welding resistance and chemical stability at high temperatures of the material are also improved by containing the Tj compound, and this CBN-based condensed material also contains Ni, N, Co, Si,
and one or more metal components of Cr.
．． When contained in a range of 5 to 1% by weight, these components have the effect of strengthening the bonding force between bonding phases, making the material more dense. A portion of the CBN is set to a range that does not exceed the CBN, that is, 0. 〇5< Wurtzke type shelarynic nitride (volume %) < ICBN (volume %) When replaced with wurtzite type shelchloric nitride (hereinafter referred to as WBN), the toughness of the material will further increase. We obtained this knowledge.

This invention was made based on the above knowledge, and the following is the component composition, the volume ratio of CBN and WBN,
Also, the reason why the average layer thickness of the bond-strengthening metal is limited as described above will be explained.

A Component composition 'aI Ti The Ti component contains CBN particles and WBN particles as described above, as well as the above Ti compounds (TIN, TIC, TICN).
, and TiB2), and have the effect of significantly improving the sardonic properties of the material, but if the content is less than 4% by weight, the desired bond-strengthening effect cannot be secured;
If the content exceeds 5% by weight, the high-temperature hardness in particular decreases, so the content was set at 4 to 25% by weight.

'bl TIN, TIC, TICN, and TiB2 These components have the effect of improving the wear resistance, welding resistance, and high-temperature chemical stability of the material, but if their content is less than 5% by weight, the above-mentioned The desired effect is not obtained,
On the other hand, if the content exceeds 40% by weight, the rutting property will deteriorate, so the content was set at 5 to 4% by weight.

[cl Ni, Co, Si, and Cr These metal components have the effect of densifying the binder phase and further improving the strength and impact resistance of the material, so these properties are particularly important. It is contained as needed when required, but if the content is less than 0.5% by weight, the desired effect cannot be obtained in the above action, while if it is contained in excess of 1% by weight, the hardness decreases. Since the content becomes significant, its content is reduced to 0.
．． The content was determined to be 5 to 10% by weight.

B Volume ratio of CBN When the ratio of CBN to the binder phase is less than 4 tsubo volume %, the ratio of relatively hard CBN is too small to ensure the desired wear resistance; If it exceeds 40 to 9% by volume, the proportion of the binder phase becomes relatively too small and the quality deteriorates, so the volume proportion was set at 40 to 9% by volume.

C WBN substitution ratio WBN has the effect of further improving the graininess of the material, so when particularly high toughness is required, CB
Although N is contained in a partially substituted form, the substitution ratio,
In other words, WBN (capacity%)/CBN (capacity%) is 0.0
If the substitution ratio is less than 5, the desired rutting property improvement effect cannot be obtained, while if the substitution ratio exceeds 1, that is, WBN relative to CBN.
If the amount of CBN is higher than that of WB, the hardness of the material will decrease and the wear resistance will decrease.
When replacing with N,.

-〇5＜Mizowaka・Must satisfy the following conditions.

D Average layer thickness of Ti: The average layer thickness is 0. Below Kozuke, CBN particles and W
It is not possible to secure sufficient bonding strength between the BN particles and the binder phase, and on the other hand, if the average layer thickness exceeds 1 mm, the hardness of the material will decrease. The thickness was determined to be 0.1 to 1 Am.

The ultra-high pressure bonded material of the present invention is produced by first coating the surface of CBN powder and, if necessary, WBN powder using a method such as an electroless plating method, a CVD method, a PVD method, or a PCVD method. , Ti is coated with an average layer thickness of 0.1 to lr, and if necessary, TIN, T is coated on the Ti coating layer.
One or two of IC, TICN, and TiB2
The Ti-coated C
BN powder and WBN powder, and Ti, TIN, T
One or two of IC, TICN, and TiB2
CBN powder and WBN powder which are double coated with more than one species, as well as TIN powder, TIC powder, TICN powder, Ti string powder,
Ni powder, Co powder, mountain powder, Si powder, Cr powder, and alloy powder of two or more of these metals are prepared as raw material powders, appropriately selected from these raw material powders and blended into a predetermined composition, After mixing this blended powder under normal conditions, it is placed in a metal container in the form of powder or green compact, vacuum degassed and sealed, and then this sealed container is used, for example, in Japanese Patent Publication No. 36-23463. Attach it to an ultra-high pressure and high temperature generator as described in the publication, raise the pressure and temperature, and maintain the pressure and temperature within the range of pressure: 40 to 6 plates B, temperature: 1200 to 1600 qo for several minutes to several tens of minutes. It can be manufactured by a basic process consisting of cooling, then finally releasing the pressure.

Next, the ultra-high pressure lathered material of the present invention will be specifically explained using examples.

Example 1 Using the known PVD method and CVD method, the first
Coated CBN powder and coated WBN powder shown in the table were prepared and these powders were TIN with average particle size: 2rm.
Powder, TIC powder with the same 2-meter, TICN powder with the same 2r, TiB2 powder with the same 2" kite, all with the same 2
Ni powder, mountain powder, Co powder, Si powder,
and Cr powder are prepared as raw material powders, and these raw material powders are blended into the compositions shown in Table 1, and these blended powders are wet mixed in a ball mill for about 2 hours, then dried, and then this mixed powder is mixed. Powder: 12 willows? After filling and charging the cemented carbide plates with the dimensions of diameter: 12 yanagi x thickness: 1.5 into a European steel container, degassing in a vacuum and sealing, This sealed container is placed in a known ultra-high pressure and high temperature generator, pressure: 5cm, temperature:
By the basic process of condensing at 13,000C and holding time: 10 minutes, and finally cooling and gradually lowering the pressure, the present invention has a final component composition that is substantially the same as the blended composition. High-pressure phosphorized materials 1 to 12 were produced, respectively.

Next, the ultra-high pressure bonding materials 1 to 1 of the present invention obtained as a result
Regarding 2, work material: die steel (SKD-11, hardness:
HRC59), cutting speed: 120/mjn, feed: 0
．． A cutting test was conducted under the following conditions: depth of cut to the 1st side 'rev: 0.5 feet, no cutting oil, and the cutting time until the flank wear of the cutting edge reached the 0.2 column, and the work material:
A die steel round bar with an outer diameter of 130 mm (S
KD-61, hardness: HRC53), cutting speed: 110/min, depth of cut: 0.5 skin, feed: 0.05, 0.1
, 0.15, 0.2, 0.3, and 0.4 ribs/rev
．． An intermittent cutting test was conducted under the following conditions: cutting time for each feed: 3 minutes, cutting oil: absent, and the feed rate at the time when chipping was observed on the cutting edge was checked. The cutting test results are shown in Table 1. Ships and shipsIn Table 1, the dispersed phase is composed of CBN, but commercially available ultra-high pressure lathering materials with a different binder phase, that is, materials whose binder phase is composed of a metal consisting of AI-Co, are listed. (hereinafter referred to as conventional ultra-high-pressure condensed material 1) and a material whose binder phase is a ceramic compound of TICN (hereinafter referred to as conventional ultra-high-pressure condensed material 2) under the same conditions are also shown.

As shown in Table 1, the ultra-high pressure competitive twill materials 1 to 1 of the present invention
No. 2 has both excellent wear resistance and rutting resistance, so it showed excellent cutting performance in all cutting tests. In the conventional ultra-high pressure lathered materials 1 and 2, which have inferior properties,
It is clear that both tests do not give satisfactory results. As mentioned above, the ultra-high pressure curing material of the present invention has excellent wear resistance and toughness, as well as high hardness, as well as excellent heat resistance and high temperature strength. It exhibits excellent performance not only as cutting tools, but also as wear-resistant tools such as bearings and wire drawing dies.

Claims (1)

[Claims] 1. Ti as a bond-strengthening metal: 4 to 25% by weight, Ti
one of carbides, nitrides, carbonitrides, and borides of
Species or two or more species: Contains 5 to 40% by weight, with the remainder consisting of cubic boron nitride and unavoidable impurities, and the cubic boron nitride occupies 40 to 90% by volume, and the above bonds The reinforcing metal is cubic boron nitride with a thickness of 0.1 to 1μ
A high-toughness boron nitride-based ultra-high pressure sintered material for cutting and wear-resistant tools, characterized by having an enclosed structure with an average layer thickness of m. 2 Ti as bond-strengthening metal: 4 to 25% by weight, Ti
one of carbides, nitrides, carbonitrides, and borides of
species or two or more species: Contains 5 to 40% by weight, and further contains N
i, Al, Co, Si, and Cr: 0.5 to 10% by weight; the remainder is cubic boron nitride and unavoidable impurities; Boron nitride occupies 40 to 90% by volume, and
A high-toughness boron nitride-based ultra-high pressure sintered material for cutting and wear-resistant tools, characterized in that the bond-strengthening metal has a structure in which cubic boron nitride is surrounded by an average layer thickness of 0.1 to 1 μm. 3 Ti as bond-strengthening metal: 4-25% by weight, Ti
one of carbides, nitrides, carbonitrides, and borides of
Species or two or more species: Contains 5 to 40% by weight, with the remainder consisting of cubic boron nitride, wurtzite boron nitride, and unavoidable impurities, and cubic boron nitride and wurtzite boron nitride are It accounts for 40-90%, and
0.05 < (wurtzite boron nitride (volume %)) / (cubic boron nitride (volume %)) A high-toughness boron nitride ultra-high pressure sintered material for cutting and wear-resistant tools, characterized by having an enclosed structure with an average layer thickness of 1 to 1 μm. 4 Ti as bond-strengthening metal: 4-25% by weight, Ti
one of carbides, nitrides, carbonitrides, and borides of
species or two or more species: Contains 5 to 40% by weight, and further contains N
i, Al, Co, Si, and Cr: 0.5 to 10% by weight, and the remainder consists of cubic boron nitride, wurtzite boron nitride, and inevitable impurities. and cubic boron nitride and wurtzite boron nitride occupy 40 to 90% by volume, and 0.0
5 < (wurtzite boron nitride (volume %)) / (cubic boron nitride (volume %))
A high-toughness boron nitride-based ultra-high pressure sintered material for cutting and wear-resistant tools, characterized by having an enclosed structure with an average layer thickness of ~1 μm.