JPS601389B2 - Cubic boron nitride-based ultra-high pressure sintered material for cutting tools and wear-resistant tools - Google Patents

Description

[Detailed description of the invention] This invention provides high hardness, excellent wear resistance,
It has heat resistance and high-temperature strength, and can be used as a cutting tool for work materials such as high-speed steel, N-based or Co-based super alloys, which require these properties, and as a wear-resistant tool for bearings, wire drawing dies, etc. The present invention relates to a cubic boron nitride (hereinafter referred to as CBN)-based ultra-high pressure sintered material suitable for use as a tool.

Conventionally, tungsten carbide (hereinafter referred to as WC)-based material, which has relatively high hardness and excellent grade, has been widely used in the production of cutting tools and wear-resistant tools of this type.

However, since this WC-based sintered material does not have sufficient wear resistance, it is currently unable to exhibit sufficiently satisfactory performance under today's harsh usage environments. on the other hand,
In recent years, CBN-based ultra-high pressure sintered materials, which have extremely high wear resistance and are suitable for use as cutting tools and wear-resistant tools, have been developed to solve the problems of conventional WC-based sintered materials. Proposed.

This CBN-based ultra-high pressure fired material can be roughly divided into two types depending on the binder phase of the CBN grains. One is titanium nitride (TIN), titanium carbide (T
It is composed of a binder phase mainly composed of components such as IC), aluminum nitride (AIN), and aluminum oxide (AI203).

However, in the former case, since the binder phase is composed of metal, it easily softens at high temperatures, and therefore is unsatisfactory due to lack of wear resistance when used under harsh conditions that generate a large amount of heat. As a result, when used for cutting high-hardness steel such as die steel, it can only be applied under conditions with little heat generation (low-load cutting conditions). be.
In addition, in the latter CBN-based ultra-high pressure sintered material whose binder phase is a ceramic compound, in addition to the fact that the ceramic itself is inherently brittle, it also has poor maintenance properties, so it has poor heat resistance and wear resistance. However, due to its lack of ballability, it is prone to chipping and breakage under cutting conditions where a large impact force is applied to the cutting edge (for example, when milling high-speed steel). Therefore, the present inventors aimed to solve the problems of the conventional CBN-based ultra-high-pressure sintered materials as described above.As a result of research focusing on the bonding phase, we found that the bonding phase of CBN particles was Assuming that the W-Tj-C-N alloy matrix has a structure in which hard carbonitrides are precipitated, the resulting CBN-based ultra-high pressure fried striped material has "high hardness, wear resistance, It has excellent ballability, heat resistance, and high-temperature strength, and is chemically extremely stable.
Furthermore, when one or two of AI, B, Zr, and Sj are contained in this, the bonding strength between CBN grains and at the interface between the CBN grains and the binder phase is further increased due to the deoxidizing effect of these components. As it becomes stronger, it has better grain quality, and it also has Ni, Co, and F.
When one or more of e, Mn, and Cu are contained, the bonding force between bonding phases is further strengthened during the bonding process under ultra-high pressure, and densification is facilitated. As a result, they found that strength can be improved.

Therefore, this invention was made based on the above-mentioned knowledge, and is expressed in weight% (hereinafter all percentages are expressed as weight%).
), W: 15-80%, Ti: 0.8-20%, C: 0.1-4.0%, N: 0.1-3.0%, and.

5≦Poisonous Pig≦. - satisfies the following, and if necessary, one or more of AI, B, Zr, and Si (hereinafter collectively referred to as toughness-improving components): 0.
1 to 2%, Ni, one or more of Co, Fe, Mn, and Cu (hereinafter collectively referred to as strength improving components): 0.1 to 2%, CBN and unavoidable impurities: CBN and unavoidable impurities. This CBN-based ultra-high pressure sintered material has a linear weave in which hard carbonitrides are precipitated, and exhibits outstanding performance particularly when used as cutting tools and wear-resistant tools.

The reason why the CBN-based ultra-high pressure striation material of the present invention has the above-mentioned excellent properties is because of the combination of CBN powder and W of a predetermined composition.
-Ti-C-N alloy powder or W-Ti- of a specified composition
When a raw material powder consisting of a mixed powder blended to form a C-N alloy is sintered under ultra-high pressure in a mixed state, the alloy powder or alloyed powder plastically flows during sintering to form CBN particles. As a result of being sintered in a manner that surrounds the CBN particles, the grain growth of the CBN particles during sintering is suppressed, and scaling and elasticity are promoted, resulting in strength, The plowability is further improved, and the resulting binder phase is a layered eutectic structure of a solid binary system of a W-rich metal phase and a hard carbonitride phase, or a precipitated primary hard carbonitride particle. Because it has a layered structure,
It is thought that it has excellent wear resistance, high hardness, and heat resistance.

Next, in the CBN-based ultra-high pressure sintered material of this invention,
The reason why the component composition range was limited as described above will be explained.

(a) The WW component has the effect of improving the heat resistance of the binder phase and strengthening the bonding force between the CBN particles and the binder phase, but if its content is less than 15%, the desired effect is not achieved. On the other hand, if the content exceeds 80%, the proportion of the metal phase in the binder phase becomes too large and the wear resistance decreases.
It was set as 0%.

'b} Ti The Ti component mainly forms layered carbonitrides (Ti-W composite carbonitrides in which some W is dissolved as a solid solution) in the binder phase to improve the wear resistance (hardness) of the material. However, if the content is less than 0.8%, the desired effect cannot be obtained, while if the content exceeds 20%, in addition to layered carbonitrides, excessive primary crystals may be produced. Particulate carbonitrides begin to form, and as a result, although the wear resistance is good, the toughness deteriorates significantly, so the content should be reduced from 0.8 to 20.
%.

{c'C and N The C and N components have the effect of improving the wear resistance of the material by partially dissolving into the base material and the rest forming hard carbonitrides with W and/or Ti. , if the content is less than 0.1% C and 0.1% N, it is impossible to form a predetermined amount of hard carbonitride, and the relative proportion of the alloy phase in the binder phase increases. is too large and it is not possible to secure the desired excellent wear resistance. On the other hand, if C: exceeds 4.0% and N: exceeds 3.0%,
Since the amount of hard carbonitrides in the binder phase becomes too large and the binder phase itself and the entire Momo Nagozu material become arms, the content of each is reduced to C: 0.1 to 4.0. %, N:
It was set at 0.1 to 3.0%.

In addition, if the value of car hair %N% is less than low, the proportion of N in the hard carbonitride becomes relatively large, and the bonding strength of the hard carbonitride with the base material decreases, resulting in a material becomes arm-shaped, and on the other hand, when the value of C re-nose value exceeds the value, the ratio of ○ in hard carbonitride increases compared to N, and as a result,
It was determined that the abrasion resistance of the material deteriorated) or that the nasal sound was 5 to 1.

As mentioned above, the AI, B, Zr, and Si components have the effect of further improving the rolling properties of the material, so they are included when particularly high rutting properties are required.
If it is less than 1%, the desired rice grain improvement effect cannot be obtained;
If it is contained in excess of
Its content was determined to be 0.1 to 2%. {e} Like the strength-improving components, Ni, Co, Fe, Mn, and Cu components have the effect of further increasing the strength of the material, but if their content is less than 0.1%, the desired strength improvement is not achieved. no effect,
On the other hand, if the content exceeds 2%, the high-temperature strength will decrease, so the content of these components is set at 0.1 to 2% when particularly high strength is required.

In addition, CB in the CBN-based ultra-high pressure bonding material of this invention
The content of N is preferably 18 to 60%, because if the content is less than 18%, it will be difficult to secure the desired excellent wear resistance, and on the other hand, if the content exceeds 60%, it will be difficult to secure the desired excellent wear resistance. This is because the sardine quality of the material is significantly reduced.

Further, the CBN-based sintered material of the present invention usually uses CBN powder as raw material powder and W-Ti-C-N alloy powder or mixed powder blended to have a predetermined binder phase composition. The raw material powders are blended in a predetermined ratio and mixed under normal conditions.The resulting mixed powder is then placed in a metal container, degassed at a temperature of 800 to 1200 qo, and vacuum sealed. Loaded into high pressure generator, pressure: 40-70Kb, temperature: 1300-1700q
It can be manufactured by a series of ultra-high-pressure firing steps in which the product is held under the ultra-high pressure and high temperature conditions of ○ for about 5 minutes or more, and then cooled to lower the pressure.

Next, the CBN-based superlocalized pressure sintered material of the present invention will be explained using Examples and in comparison with Comparative Examples.

Example 1 As a raw material powder, a commercially available CBN powder having an average particle size of 2 mounds, and a CBN powder having an average particle size of 1 mound and Ti: 17
%, C: 2.7%, N: 1.3%, and W: the remainder, produced by a high-temperature plasma method.
N alloy powder is prepared, and these raw material powders are converted into CBN powder:
55%, W-Ti-C-N alloy powder: 45%, and after wet mixing this blended powder in a ball mill for 2 hours, it was packed into a Mo container with an outer diameter of 12. After degassing by exposing it to a vacuum, it is sealed, and then the sealed container is placed in a known ultra-high pressure and high temperature generator, and the pressure:
Ultra-high pressure sintering was performed under the conditions of 5 arc b, temperature: 145,000, holding time: 3 minutes, and after finally cooling, the pressure was gradually lowered to produce W: 34.8%, Ti: 7. 0%, C:
1.1% to N: 0.5%, CBN and inevitable impurities:
Ultra-high pressure sintered material 1 of the present invention having a final component composition consisting of the remainder was manufactured.

Next, the ultra-high pressure sintered material 1 of the present invention obtained as a result,
Regarding the commercially available ultra-high pressure sintered material containing TN: 15% prepared for comparison, work material: SNCM-8 (Hardness HRC:
52), Cutting speed: 120'min, Feed: 0.12
skin/rev. , Depth of cut: 0.5 side, Cutting oil: No condition (hereinafter referred to as cutting condition A), and Work material: Die steel S
KD-11 (hardness HRC: 61), cutting speed: 110 skin/min, feed: 0.1 skin'rev, depth of cut: 0.3
A cutting test was conducted without ribs or cutting oil (hereinafter referred to as cutting condition B), and the cutting time until the flank wear reached 0.2 skin was measured.

As a result, under cutting conditions A, ultra-high pressure sintered material 1 of the present invention:
48 minutes, commercially available ultra-high pressure sintered material: 1 piece, and cutting condition B shows the ultra-high pressure sintered material of the present invention: 1:56 minutes, commercially available ultra-high pressure sintered material: 1 piece, respectively. From the results, it is clear that the ultra-high pressure sintered material 1 of the present invention exhibits a much better cutting performance than commercially available materials. Example 2 Commercially available CB having an average grain size of 2rm was used as a raw material powder
N powder, various W-Ti having the composition shown in Table 1, and each having an average particle size of 2 μm.
-C-N alloy powder, average particle size: 2mm powder, B powder, 2mm Zr powder, 3rm S method powder, 2Am Ni powder Co powder on the skin, Fe powder on the skin of the same 2 mountains, M-chomasue of the 2 Buddhas, and C on the skin of the 2 mountains.
The ultra-high pressure sintered materials 2 to 16 of the present invention and the comparative ultra-high pressure sintered materials were prepared under the same conditions as in Example 1, except that u powder was prepared and these raw material powders were blended into the composition shown in Table 1. Materials 1 and 2 were produced respectively.

The final component compositions of the ultra-high pressure bonded materials 2 to 16 of the present invention and comparative ultra-high pressure fired materials 1 and 2 obtained as a result and the cutting test results under cutting condition A in Example 1 were
Shown in the table.

Table 1 also shows the occurrence of chipping on the cutting edge after the cutting test. From the results shown in Table 1, in the comparative ultra-high pressure sintered material 1, which has a high content of C component outside the range of the present invention, chipping occurs significantly due to lack of graininess, and as a result, the life time is shortened. In comparative ultra-high pressure bridging material 2, which is extremely short and has a low CBN content which is also outside the scope of the present invention,
Due to the lack of wear resistance, the lifespan is shortened and it becomes a problem.

On the other hand, it is clear that all of the ultra-high pressure sintered materials 2 to 16 of the present invention exhibit excellent cutting performance.
Ship Example 3 As raw material powders, commercially available CBN powder, TIC powder, TIN powder, WC powder, and W powder, all of which have an average particle size of 2 mounds, as well as 2 m kite mound powder and 2 mound diameter B powder, Zd powder from the same 2nd mountain surface, Si powder from the 3rd mountain surface, Ni powder from the same 2nd mountain surface, Co powder from the same 1st surface, Fe powder from the same 2nd surface, Mn powder from the same 2nd surface, The ultra-high pressure brazed material of the present invention was prepared under the same conditions as in Example 1, except that Cu powder with a diameter of 2 m was prepared and these raw powders were blended to have the final component composition shown in Table 2. 17-30 and comparative ultra-high pressure Akatsuki silk materials 3-5 were prepared, respectively.

Table 2 shows the test results of the resulting ultra-high pressure bonded material under cutting condition A in Example 1 and the occurrence of chipping after the test.

From the results shown in Table 2, it can be seen that in this example, as in Example 2, the ultra-high pressure scale material 1 of the present invention
Nos. 7 to 30 all showed excellent cutting properties, whereas comparative ultra-high pressure Akatsuki materials Nos. 3 to 5, whose component contents were outside the range of the present invention, all showed poor cutting performance. It has become a thing. Table 2 As mentioned above, the CBN-based ultra-high pressure scale feeding material of the present invention is:
It has high hardness, excellent wear resistance, rutting resistance, heat resistance, and high temperature strength, so it can be used as a cutting tool for work materials such as high-speed steel, N-based or Co-based superalloy, which require these properties. It has industrially useful properties such as being able to stably maintain extremely excellent performance over a long period of time, not only when it is used, but also when used as wear-resistant tools such as bearings and wire drawing dies.

Claims (1)

[Claims] 1 W: 15-80%, Ti: 0.8-20%, C: 0
．． 1 to 4.0%, N: 0.1 to 3.0%, and satisfies 0.5≦(C%)/(C%+N%)≦1, with the remainder being cubic nitride. element (however, cubic boron nitride: 1
8 to 60%) and unavoidable impurities (wt%), and the binder phase of cubic boron nitride grains is
A cubic boron nitride-based ultra-high pressure sintered material for cutting tools and wear-resistant tools, characterized by having a structure in which hard carbonitrides are precipitated in a W-Ti-C-N alloy matrix. 2 W: 15-80%, Ti: 0.8-20%, C: 0
．． 1 to 4.0%, N: 0.1 to 3.0%, and satisfies 0.5≦(C%)/(C%+N%)≦1, and further contains Al, B, Zr, and one or more of Si: 0.1 to 2%, and the remainder consists of cubic boron nitride (however, cubic boron nitride: 18 to 60% contained) and unavoidable impurities. composition (more than % by weight), and the binder phase of the cubic boron nitride grains has a structure in which hard carbonitrides are precipitated in the matrix of the W-Ti-C-N alloy. Cubic boron nitride-based ultra-high pressure sintered material for cutting tools and wear-resistant tools. 3 W: 15-80%, Ti: 0.8-20%, C: 0
．． 1 to 4.0%, N: 0.1 to 3.0%, and satisfies 0.5≦(C%)/(C%+N%)≦1, and further contains Ni, Co, Fe, Contains one or more of Mn and Cu: 0.1 to 2%, and the remainder is cubic boron nitride (cubic boron nitride: 18 to 60%).
W-Ti-
A cubic boron nitride-based ultra-high pressure sintered material for cutting tools and wear-resistant tools, characterized by having a structure in which hard carbonitrides are precipitated in a C--N alloy matrix. 4 W: 15-80%, Ti: 0.8-20%, C: 0
．． 1 to 4.0%, N: 0.1 to 3.0%, and satisfies 0.5≦(C%)/(C%+N%)≦1, and further contains Al, B, Zr, and one or more of Si: 0.1 to 2%, and one or more of Ni, Co, Fe, Mn, and Cu: 0.1 to 2%, The remainder is cubic boron nitride (cubic boron nitride; containing 18 to 60%) and unavoidable impurities (weight percent), and the binder phase of the cubic boron nitride grains is , a cubic boron nitride-based ultra-high pressure sintered material for cutting tools and wear-resistant tools, characterized by having a structure in which hard carbonitrides are precipitated in a matrix of W-Ti-C-N alloy.