JPS5860679A - High tenacity boron nitride base super high pressure sintering material for cutting and abrasion-resistant tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is particularly applicable to high-speed steel, which has excellent toughness and wear resistance, high hardness, and excellent heat resistance and high-temperature strength, and which requires these properties. N1 group or CO
The present invention relates to a boron nitride-based ultra-high pressure sintered material suitable for use as a cutting tool for rigid materials such as super alloys, and as wear-resistant tools such as bearings and wire drawing dies.

In recent years, cubic boron nitride-based ultra-high pressure sintered 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 as cutting tools and wear-resistant tools. It is proposed that.

This CBN-based sintered material can be roughly divided into two types depending on the binder phase of CBN particles forming the dispersed phase.
One type has a binder phase composed of a metal whose main component is an iron group metal or AM, and the other type has a binder phase made of a ceramic compound whose main component is titanium nitride, titanium carbide, aluminum nitride, or aluminum oxide. It is composed of However, in the former, since the binder phase is metal as mentioned above, it easily softens at high temperatures, and therefore, when used as a cutting tool, for example, it can withstand severe cutting conditions that generate a large amount of heat. Due to the lack of abrasiveness, sufficient cutting performance cannot be expected, and it can only be used under conditions where there is little heat generation, that is, under low load conditions. In addition, the latter has excellent heat resistance and wear resistance due to the above reasons, but on the other hand, lack of toughness cannot be avoided, and for example, when cutting high-speed steel, the cutting edge has a large Under cutting conditions where impact force is applied, chipping and breakage are likely to occur.

In order to solve the problems of the two types of conventional CBN-based sintered materials described in 1. and -, a C''BN-based sintered material in which the binder phase is composed of a metal and a ceramic compound has also been proposed. However, even this CBN-based sintered material does not exhibit sufficiently satisfactory toughness, 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 may deteriorate. It is easy for defects to occur.

This was made clear by detailed observation of the boundary between the CBN particles and the binder phase (metal + ceramic compound) in the CBN-based sintered material using a scanning electron microscope. During sintering, the binder phase is not sufficiently injected into the minute recesses on the surface of the CBN particles, resulting in minute unbonded areas (voids) being formed at the boundary between the CBN particles and the CBN particles. The adhesion with the binder phase varies depending on the constituent components of the binder phase, but it is particularly low in the case of carbide-based 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 present inventors conducted research to obtain a CBN-based sintered material that has particularly excellent toughness and wear resistance.
Bond-strengthening nitride consisting of one or more nitrides of Ti, Hf, and Sl: 5 to 40% by weight, At,
One or more oxides of Zr and Y: 5 to 3
5% by weight, with the remainder consisting of CBN (cubic boron nitride) and unavoidable impurities, and CBN occupies 40 to 90% by volume, and the bond-strengthening nitride reduces CBN to 0. .Assuming that the structure has an enclosed structure with an average layer thickness of 1 to 2 pm, CBI comprising one part of the dispersed phase
The bond-strengthening nitride surrounded by the J powder particles has a high bond strength with the CBN particles and the above-mentioned oxides constituting the binder phase, so it strongly bonds with both of them, and the bond-strengthening nitride described above is used in raw material preparation. Sometimes chemical vapor deposition (
CVD method), plasma chemical vapor deposition method (PCVD method)
, physical vapor deposition (PVD), etc., so that there is no unbonded part (void) at the boundary between the CBN particles and the bond-strengthening nitride surrounding layer. Not only does it have high toughness, but it also has excellent wear resistance.Furthermore, this CB and J-based sintered material has N 1+ A+! + CO+ and S
1 know (7) l, fI4! Or 2 stacks - L to 0
．． When contained in the range of 5 to 15% by weight, these components have a deoxidizing effect and an effect of strengthening the bonding force between bonding phases, making the material denser and further increasing the CBN content.
We have obtained the knowledge that a part of CBN in the base sintered material is within a range where it does not exceed CBN, that is, it becomes .

This invention was made based on the above findings, and the reason why the component composition, the volume ratio of CBN and WBH, and the average layer thickness of the bond-strengthening nitride surrounding layer were limited as described above is explained below. explain.

A, Component composition (a) Nitride Nitride of Ti, Hf, and Si (hereinafter referred to as TiN, Hf
N.

and Si3N4) is bonded to strengthen the CBN particles and the oxide that forms the binder phase, and is coated on the surface of the CBN particles during raw material preparation to prevent toughness deterioration at the boundary. However, if its content is less than 5% by weight, C
It is not possible to completely surround the surface of the BN particles, and therefore the desired effect cannot be obtained in said action, while 40% by weight
Since the abrasion resistance will decrease if the content exceeds 3, (b
) Oxides of AQ, Zr, and Y (hereinafter referred to as At!203,
ZrO2° and Y2O3) have the effect of improving the chemical stability of the material in practical use.
If the content is less than 5% by weight, the desired positive effect on chemical stability will not be observed, while if the content exceeds 15% by weight, the toughness of the material will decrease. was set at 5 to 15% by weight.

(C) Metal components Nj, AJCo, and Sl have the effect of deoxidizing and strengthening the bonding force between bonding phases, and the inclusion of these metal components 9 makes the material even more dense, so this is necessary. However, if the content is 0.
If the content is less than 5% by weight, the desired effect cannot be obtained, while if the content exceeds 15% by weight, the wear resistance will deteriorate.
It was determined that

B, volume ratio of C13N When the ratio of CBH to the binder phase is less than 40 volume, the ratio of relatively hard CBN is too small to ensure the desired wear resistance, while on the other hand, when the ratio of CBH is 90 If the volume exceeds 1, the proportion of the binder phase becomes relatively too small and the toughness deteriorates, so the volume ratio was set at 40 to 90.

The substitution ratio WBN of C, WBH has the effect of further improving the toughness of the material, so when particularly high toughness is required, CBH may be added as needed.
is contained in a partially substituted form, but the substitution ratio, that is, WBN (@ volume ratio) / CBN (capacity ratio) is 0105
If it is less than l, the desired high toughness cannot be secured;
, i.e. relative to CBN W
When the amount of BNO is higher, the hardness of the material decreases and the wear resistance deteriorates. Therefore, when replacing a part of Cf3N with WBN, W B N 0.05 (-( 1 (ShBN conditions must be met.

D, average layer thickness of bond-strengthening nitride If the average layer thickness is less than 0.1 μm, it is a CBN particle.

Alternatively, it is not possible to sufficiently strengthen the bond between CBN particles and WBN particles and the binder phase, and on the other hand, if the average layer thickness exceeds 2 μm, the amount of nitride becomes relatively too large. 9. As a result, the wear resistance of the material decreases, so the average layer thickness should be adjusted to 0.1 to 2.
It was determined as μm.

In addition, the ultra-high pressure sintered material of this invention is not sintered, but is coated on the surface of the CBN powder and, if necessary, the WBN powder by the CVD method.
riN using PCVD method, PVD method, etc.
)IfN, and 513N4 with a layer thickness of 0.1-2 μm, and if necessary, coated with Ag2O3, ZrO2, and Y2O5.
One of these or 28! Nitride-covered CBN powder and WBN powder prepared in this way by multi-layer vapor deposition of the above,
and nitride and oxide coated CBN powder and WB
N powder, JV, 03 powder + Z r O2 powder lY
2O3 powder, Ni powder, AQ powder, Co powder, S1 powder, and alloy powder of two or more of these metals are prepared as raw material powders, and the raw material powders are appropriately selected and blended into a predetermined composition. After mixing this blended powder under normal conditions, it is placed in a metal container together with a cemented carbide plate, etc. as required in powder or molded state, and heated to a temperature of 800 to 1200°C. After performing vacuum degassing and sealing, the sealed container is attached to an ultra-high pressure and high temperature generator such as that described in Japanese Patent Publication No. 36-23463, the pressure and temperature are increased, and pressure crabs 40~'i 'oKl), temperature: After maintaining the pressure and temperature within the range of 1200 to 1600°C for several minutes to several tens of minutes,
It can be manufactured by a basic process consisting of cooling and finally releasing the pressure.

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

Example 1 As raw material powder, coated CBN powder and coated WBN powder were prepared using the known CVD method or PCV+ method in the state shown in Table 1, respectively, and the coated WBN powder had an average particle diameter of μm.
Al! 203 powder, 2 μm ZrO□ powder,
The same 2 μm Y, 03 powder, and both average particle size: 2
Prepare Ae powder, 141 powder, Co powder, and S1 powder, each of which has a particle diameter of Then, this mixed powder was packed into a mild steel container with an outer diameter of 12 mm and heated to a temperature of 800°C.
After vacuum degassing and sealing, it was installed in a known ultra-high pressure and high temperature generator, and the pressure was 50 to 60 +), temperature: 130
The basic process consists of sintering at 0-1400°C, holding time: 15-20 minutes, and finally cooling and gradually lowering the pressure to have a final component composition that is substantially the same as the blended composition. Ultra-high pressure sintered materials 1 to 18 of the present invention were manufactured.

Next, the ultra-high pressure sintered materials 1 to 1 of the present invention obtained as a result
Work material: Die steel (SKI) -11
, hardness: HTIC60), cutting speed: 110m/mi
.

Feed: o, mm/rev, depth of cut, 'O-
A cutting test (referred to as cutting test A) to measure the life time until the flank wear of the cutting edge reaches 0.2 mm when cutting under the conditions of 3mm + cutting oil: and cutting material: along the longitudinal direction. A die steel round bar (S
KD-61, hardness: HRC55), cutting speed loom
/M, Depth of cut: 0-5mm + Feed 9: o, o5゜0, J
O, 15, 0, 2, 0, 3, and 0.4 myn
/r ev, .

A cutting test (referred to as cutting test B) was conducted to check the feed rate at which chipping was observed on the cutting edge during cutting under the following conditions: cutting time for each feed: 2 minutes, no cutting oil. The results of these cutting tests are shown in Table 2. In addition, the second
The table shows commercially available ultra-high pressure sintered materials (conventionally referred to as ultra-high pressure sintered materials) in which the dispersed phase is composed of CBN and the binder phase is ICN, and the binder phase is composed of CO. The cutting test results of the commercially available ultra-high pressure sintered material shown in Table 2 (referred to as conventional ultra-high pressure sintered material 2) under the same conditions are shown.

As shown in Table 2, the ultra-high pressure sintered materials 1 to 1 of the present invention
Since both have excellent wear resistance and toughness, compared to the conventional ultra-high pressure sintered material 1.2 which is inferior in either of these properties, It is clear that the material also exhibits excellent cutting performance.

Example 2 The coated C13N powder and the coated W B' N powder shown in Table 3 were used, and a mixed powder or green compact was prepared with a composition consisting of Co: 12% by weight, wC, and unavoidable impurities: the remainder. Diameter: 11.5miφ
The outer diameter of the cemented carbide plate and one piece.

It was packed in a Mo container with a diameter of 12 mm, and the container was heated to a temperature of 900° C. in H2 gas for cleaning treatment before vacuum degassing treatment under substantially the same conditions as in Example 1. Ultra-high pressure sintered materials 19 to 26 of the present invention having the same final component composition as shown in Table 3 were manufactured.

The results of cutting tests conducted on the ultra-high pressure sintered materials 19 to 26 of the present invention under the above cutting conditions A and B are shown in the fourth section.
It is shown in the table along with the Vickers hardness.

As shown in Table 4, the ultra-high pressure sintered materials 19-
It is clear that, as in the case of Example 1, No. 26 also exhibits a much superior cutting performance compared to conventional ultra-high pressure sintered materials.

As shown in Table 4 above, the ultra-high pressure sintered material of the present invention has excellent wear resistance and toughness, and also has high hardness, excellent heat resistance, and high temperature strength. It exhibits excellent performance not only in cutting tools that require high performance, but also in wear-resistant tools such as bearings and wire drawing dies.

Applicant: Mitsubishi Metals Corporation Agent Tomi 1) Kazuo

Claims (4)

[Claims] (1) One or more nitrides of Ti, If, and °C1: 5 to 40% by weight + Ai! ,
One or two stacks of Zr and Y - H oxide: 5
~35% by weight, with the remainder consisting of cubic boron nitride and unavoidable impurities, and when the cubic boron nitride occupies 40 to 90 qb by volume, the nitride has a composition of cubic boron nitride and unavoidable impurities. A high-toughness boron nitride-based ultra-high pressure sintered material for cutting and wear-resistant tools, characterized by having a structure in which boron nitride is surrounded by an average layer thickness of 0.1 to 2 μm. (2) One or two stacks of Ti, Hf, and Sl - Nitride of H: 5 to 40% by weight, AQ, Zr, and Y
5 to 35% by weight of one or more oxides of Nlr AE r Co , and Sl
Contains one or two stacked fibers J-: 0.5 to 15% by weight, with the remainder consisting of cubic boron nitride and unavoidable impurities, and the volume proportion of cubic boron nitride is 40 to 90%. %
The nitride occupies 0.1% of cubic boron nitride.
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 ~2 μm. (3) One or two of Ti, Hf, and Sl
Contains 5 to 40% by weight of one or more nitrides, 5 to 35% by weight of one or more oxides of AA, Zr, and Y, and the remainder is cubic boron nitride and wurtzite boron nitride. has a composition consisting of unavoidable impurities, and cubic boron nitride and wurtzite boron nitride account for 40 to 90% by volume, and also satisfies the following: A high-toughness boron nitride-based ultra-high pressure sintered material for patented and wear-resistant tools, characterized by having a structure in which boron nitride is surrounded by an average layer thickness of 0.1 to 2 μm. (4) Nitride of one or two stacks of I, Hf, and Sl: 5 to 40 weight% + AQ, Z
r, and one or more oxides of Y: 5 to 35
% by weight, and further Nj, At! , Co, and Sl: 0.5 to 15% by weight
and the remainder consists of cubic boron nitride, sumac type boron nitride, and unavoidable impurities, and the cubic boron nitride and sumac type boron nitride have a volume ratio of 40 to 90.
% and satisfies the following, and further has a structure in which the nitride surrounds cubic boron nitride and wurtzite boron nitride with an average layer thickness of 0.1 to 2 μm. High-toughness boron nitride-based ultra-high pressure sintered material.