JPS607022B2 - Cubic boron nitride-based ultra-high pressure sintered material for cutting tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has excellent wear resistance, toughness, deposition resistance, and thermal shock resistance, and is particularly suitable for cutting Ni-based or Co-based superalloys and high-hardness steel. The present invention relates to a cubic nitride terrace-based ultra-high pressure annealed material that is used as a cutting tool for cutting difficult materials.

In recent years, attempts have been made to use ultra-high-pressure agglomerated materials containing L cubic shelmetal nitride (hereinafter abbreviated as CBN) as a cutting tool.

This CBN-based bonding material has excellent wear resistance and is roughly divided into two types depending on the binder phase of CBN particles forming the dispersed phase. That is, one of them is one in which the binder phase is composed of an iron group metal or a metal whose main components are an iron group metal and AI, and the other is one in which the binder phase is composed of a metal such as titanium nitride, titanium carbide, aluminum nitride, or aluminum oxide. The main component is ceramic, which does not contain metal, and the binder phase is composed of ceramic. However, in the former CBN-based ultra-high pressure sintered material in which the binder phase is composed of metal,
Although the metal binder phase provides high toughness, it is easily softened at high temperatures, and therefore, when used under harsh cutting conditions that generate a large amount of heat, it may lack sufficient wear resistance and anti-sagging properties. It cannot be expected to exhibit such cutting performance, and it can only be used under conditions where there is little heat generation. On the other hand, in the latter CBN-based ultra-high pressure deposited material, ``because the binder phase is composed of ceramic,
It exhibits excellent wear resistance and welding resistance under conditions that generate a large amount of heat, but on the other hand, it cannot avoid insufficient toughness and thermal shock resistance. Pitting and chipping are likely to occur under cutting conditions where a large impact force is applied to the cutting edge.
Therefore, from the above-mentioned viewpoint, the present inventors have developed a carbon fiber that exhibits excellent cutting performance under severe cutting conditions that generate a large amount of heat and under cutting conditions that apply a large impact force to the cutting edge.
Develop a BN-based ultra-high-pressure sintered material. As a result of research, it was found that CBN-based ultra-high-pressure sintered material contains carbides and nitrides of cape and string Z group metals of the periodic table as dispersed phase forming components in weight percent. and carbonitrides, carbides of metals in the same sheath group, and one or more of these two or more types of solid ports (hereinafter collectively referred to as metal carbonitrides) :10~60%,
Similarly to Z, a carbide of AI as a dispersed phase forming component,
One or two of nitrides, carbonitrides, and acclimated substances
Species or more (hereinafter collectively referred to as carbon/nitrogen/shelf of AI): 1 to 30%, Ni as a binder phase forming component,
One or more of Co and Fe (hereinafter collectively referred to as iron group metals): 1 to 10%, and one of Pd, Ru, and Rh as a bonding phase forming component Species or two or more (hereinafter collectively referred to as platinum group metals): 1 to 10%, containing 2, and the remainder being CBN as a dispersed phase forming component (containing 30 to 9% by volume) and unavoidable When composed of impurities, the resulting CBN-based ultra-high pressure sintered twill material has excellent wear resistance, toughness, welding resistance, and thermal shock resistance. They found that when used as a cutting tool for cutting super alloys and high-hardness steel, it exhibits excellent cutting performance even under the harshest cutting conditions.

This invention was made based on the above findings, and the reason why the component composition range was limited as described above will be explained below.

{a} Metallic charcoal.

Nitride These components have the effect of forming a dispersed phase to impart toughness and welding resistance to the material, but if their content is less than 10%, the desired immediate balling and welding resistance may not be achieved. Adhesion cannot be ensured, and if the content exceeds 60%, the wear resistance of the material deteriorates, so the content was set at 10 to 60%.

Note that the best properties are obtained when the content is 20 to 45%. {b} Mountain carbon, nitride, and shelving These components also form a dispersed phase in the same way as metal carbon and nitrides, and the inclusion of these components provides the material with significantly superior thermal shock resistance.

However, if the content is less than 1%, the desired thermal shock resistance cannot be secured, so it is necessary to contain more than 1%, but if the content exceeds 30%, the CBN particles will grow. The content should not exceed 30%, as this may lead to a decrease in the wear resistance of the material. {c} Iron group metals These components are mixed between the CBN particles forming the dispersed phase, the metal carbon/nitride particles, and the carbon/nitrogen/shelfide particles of AI, and are sintered during material production. However, if the content is less than 1%, the desired effect will not be obtained, and the material will not have the desired effect. On the other hand, if the content exceeds 10%, the binder phase becomes relatively too large and wear resistance and adhesion resistance deteriorate. It was set at ~10%.

'd} Platinum group metals These components, like iron group metals, promote silk competitiveness,
In addition to forming a binder phase and improving the balliness of the material, it also improves the heat resistance (high temperature oxidation resistance) and lacquer resistance of the binder phase, and as a result, the wear resistance of the material, especially It has the effect of improving the crater wear resistance of the cutting tool edge, but if its content is less than 1%, the desired effects cannot be obtained, while if it is contained in excess of 10%,
Since a relatively large amount of binder phase tends to increase wear resistance, particularly flank wear of the cutting edge, the content was set at 1 to 10%.

'e} Volume % of CBN This component has extremely high hardness and excellent heat resistance, so the inclusion of this component gives the material extremely excellent wear resistance and heat resistance. If the content is less than 3% by volume, the desired characteristics cannot be secured, while if it is contained in excess of 90% by volume,
If the contact ratio between CBN particles becomes too high, not only will the material form into arms, but also the agglomeration property will deteriorate, making it easier for fine pores to remain in the material, resulting in deterioration of wear resistance. Therefore, the content was set at 30 to 9% by amount of tearing.

The CBN content expressed in volume % is, for example, when comparing the specific gravity of Co and CBN, Co: 8.71
CBN: 3.48 Ta', and the difference between the two is significant. Therefore, even if the content is small in terms of weight, it becomes a considerable amount in terms of volume ratio that substantially affects the characteristics. It is. In addition, in practical use, the CBN-based ultra-high pressure sintered material for cutting tools of the present invention can be used alone or in combination with a high-rigidity material such as tungsten carbide-based cemented carbide or titanium carbide-based cermet as an indexable tip. Furthermore, these chips can be used in a state where they are attached by brazing to the tip of a holder made of tungsten carbide-based cemented carbide, hardened steel, or the like.

Next, the CBN-based deposited material of the present invention will be specifically explained with reference to Examples. Examples of raw material powders include CBN powder having an average particle size of 6 mm, TIC powder having an average particle size of 1 mm, and Zr.
C powder, HfC powder, VC powder, N ratio powder, TaC powder, Cr3C2 powder, Mo2C powder, WC powder, TIN powder, ZrN powder, HfN powder, VN powder, NbN powder,
TaN powder, TICN powder, N powder for Z, VCN powder,
TaCN powder, (Ti, W)C powder, (Zr, Ta)C
powder, (Tj, Zt) C powder, (Ti, Ta, W) C powder, (Ti, Zr) N powder, (Nb, Ta) N powder, (
Ti, W) CN powder, (Ti, Zr) CN powder, (Zr
, Mo, W) CN powder, (Ti, Ta, W) CN powder,
M4C3 powder, AIN powder, AiCN powder, AIB2 powder, Pd powder, R powder, Rh powder, Co powder, Ni powder, and Fe powder of the same type are prepared, and these raw material powders are After blending with the composition shown in the table and mixing in a ball mill under normal conditions, 2
Diameter at ℃n/flow pressure: 15 skin? × Thickness: Formed into a disc-shaped green compact with a dimension of 1.5 mm, and then these green compacts were mixed with a base material having a composition of WC: 84% and Co: 16%. Diameter molded under the same conditions: 15
Ribs? × Thickness: Insert into the container of a known ultra-high pressure and high temperature generator in a stacked state with a disc-shaped powder compact with dimensions of 3 side, pressure: 4 arc b, temperature: 1300°C, and maintained. Ultra-high-pressure sintering material 1 of the present invention having substantially the same composition as the blended composition by ultra-high-pressure sintering under conditions of time: 5 minutes
No. 28 and comparative ultra-high pressure sintered materials 1 to 10 were manufactured, respectively.

Comparative ultra-high pressure sintered materials 1 to 10 all have compositions in which the content of one of the constituent components (those marked with * in Table 1) is outside the scope of this invention. It is. QFune vertical S SatoshiFune Next, the ultra-high pressure combustion materials 1 to 2 of the present invention obtained as a result
8 and Comparative ultra-high pressure sintered materials 1 to 10, in order to measure the Vickers hardness and evaluate the toughness, fracture balling properties were determined based on the length of the crack that occurred from the tip of the indentation after the Vickers hardness measurement. In order to determine the value Kc and further evaluate the thermal shock resistance, an electrical discharge was applied to the surface, and the number of cracks formed after the electrical discharge was measured.

In addition, for the purpose of evaluating wear resistance and welding resistance, workpiece material: SKD-11 (hardness: Rockwell hardness C scale 60), depth of cut: 0.2 side, feed: 01 side/rev.
A cutting test was conducted at a cutting speed of 120 min without cutting oil, and the cutting time until the flank wear of the cutting edge reached 0.2 ribs was measured. These results are also shown in Table 1. From the results shown in Table 1, the ultra-high pressure sintered materials 1 to 28 of the present invention all have excellent ballability, thermal shock resistance,
It has wear resistance and welding resistance, and therefore shows excellent cutting performance even on difficult materials such as high-speed steel, but as seen in comparative ultra-high pressure sintered materials 1 to 10, It is clear that if the content of any of the constituent components falls outside the scope of the present invention, at least one of the above characteristics will be inferior and good cutting performance will not be obtained. be. As mentioned above, the CBN-based ultra-high pressure sintered material of the present invention has excellent ballability, thermal shock resistance, abrasion resistance, and welding resistance, so it can be used in difficult situations where these properties are required. When used as a cutting tool for cutting materials, it stably exhibits excellent cutting performance over an extremely long period of time.

Claims (1)

[Claims] 1. Carbides, nitrides, and carbonitrides of metals in groups 4a and 5a of the periodic table, carbides of metals in group 6a of the periodic table, and one or more solid solutions of two or more of these: 10 to 60 %, one or more of Al carbides, nitrides, carbonitrides, and borides: 1 to 30
%, one or more of Ni, Co, and Fe: 1 to 10%, one or more of Pd, Ru, and Rh: 1 to 10%, and the remainder is A cubic boron nitride-based ultra-high pressure sintered material for cutting tools, characterized by having a composition (the above weight %) of cubic boron nitride (containing 30 to 90% by volume) and unavoidable impurities.