JP3257255B2 - Cutting tools made of cubic boron nitride based ultra-high pressure sintered material with excellent wear resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cubic boron nitride (hereinafter referred to as CBN) -based ultra-high pressure sintered material which exhibits excellent wear resistance particularly when used for high-speed cutting of cast iron and steel. It relates to a cutting tool.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No.
As described in JP-A-303, one or more of Ti carbides, nitrides, and carbonitrides (hereinafter referred to as TiC, TiN, and TiCN, respectively) are used as a binder phase forming component. Ti charcoal / nitride: 20-4
A cutting tool comprising a CBN-based ultrahigh-pressure sintered material containing 0% and a balance of CBN as a disperse phase forming component and unavoidable impurities (above volume%, below% represents volume%). It is also known that it is used for cutting cast iron and steel.

[0003]

On the other hand, in recent years, the performance of cutting machines has been remarkably improved, and the cutting speed tends to be increased in conjunction with labor saving. When a tool is used to perform high-speed cutting, wear progresses extremely rapidly, and the tool life is shortened in a relatively short time.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoint, the above-mentioned conventional CBN-based ultra-high pressure sintered material cutting tool was focused on, and as a result of researching to improve the wear resistance thereof, the above-mentioned conventional CBN-based ultra-high pressure sintered material was manufactured. In a cutting tool, a binder phase of a CBN-based ultra-high pressure sintered material constituting the cutting tool is formed on a Ti carbon / nitride base material by using tungsten carbide (hereinafter, referred to as WC) having a particle size of 0.5 μm or less. Aluminum nitride (hereinafter, Al
N), titanium boride (hereinafter referred to as TiB ₂ ), and aluminum oxide (hereinafter referred to as Al ₂ O ₃ ), all of which account for WC: 0.1 to
2%, AlN: 1~5%, TiB 2: 3~7%,
Al ₂ O ₃ : A structure having a structure dispersed and distributed at a ratio of 5 to 15%. The resulting cutting tool made of a CBN-based ultrahigh-pressure sintered material is excellent even when it is used for high-speed cutting. The research results show that the steel shows excellent wear resistance and exhibits excellent cutting performance over a long period of time.

The present invention has been made based on the results of the above-mentioned research, and in any of the following, any one of TiC, TiN, and TiCN composed of at least one of TiC, TiN, and TiCN as a binder phase forming component. Nitride: 20-40%,
WC: 0.1 to 2%, AlN: 1 to 5%, TiB
₂ : 3 to 7%, Al ₂ O ₃ : 5 to 15%, the remainder has a composition comprising CBN as a dispersed phase forming component and unavoidable impurities, and the binder phase is Ti charcoal / nitride. WC, Al with a particle size of 0.5 μm or less
Characterized by a cutting tool made of a CBN-based ultra-high pressure sintered material having excellent wear resistance and made of a CBN-based ultra-high pressure sintered material having a structure in which N, TiB ₂ , and Al ₂ O ₃ are dispersed and distributed. It is.

Next, the reason why the component composition of the CBN-based ultrahigh-pressure sintered material constituting the cutting tool of the present invention is limited as described above will be described. (A) Ti charcoal / nitride These components have the effect of improving the strength and toughness. However, if the content is less than 20%, the desired effect cannot be obtained in the above-mentioned effect. Chipping and chipping (small chipping) easily occur in the blade, and when the content exceeds 40%, the wear resistance rapidly decreases. Therefore, the content is set to 20 to 40%. . Desirably, the content is 30 to 35%.

(B) WC, AlN, TiB ₂ , and Al ₂ O ₃ As described above, these components are dispersed and distributed in the state of coexisting with the Ti carbon / nitride matrix to strengthen the binder phase. It has the effect of contributing to the improvement of wear resistance, so that any one of these four components has a WC: less than 0.1%, Al
N: less than 1%, TiB ₂ : less than 3%, and Al
_{If the} content of ₂ O _{3 is} less than 5%, the desired effect of improving abrasion resistance cannot be obtained.
2%, AlN: 5%, TiB 2: 7%, and Al ₂ O
₃ : Since the wear resistance tends to decrease even if it exceeds 15%, the content is set to WC: 0.1 to 2%,
_{AlN: 1~5%, TiB 2:} 3~7%, and Al ₂
O _3: was defined as 5-15%. Preferably, WC:
0.5~1%, AlN: 2~4%, TiB 2: 4~6
% And Al ₂ O ₃ : 7 to 12%. Further, when the particle size of these components is larger than 0.5 μm, chipping at the starting point tends to occur, so the particle size is set to 0.5 μm or less.

[0008]

EXAMPLES As raw material powder, CBN powder having an average particle size in the range of 1 to 3.5 μm, and 0.5 to 1.8 μm
m, a TiC powder, a TiN powder, and a TiCN powder having an average particle diameter in the range of m, a WC powder, an AlN powder, a TiB ₂ powder, and an Al ₂ O ₃ powder each having a particle diameter of 0.5 μm or less. These raw material powders were blended into the compounding compositions shown in Tables 1 and 2, and at the time of mixing, the raw material powders except for the CBN powder were first lined with a WC-based cemented carbide with WC-based cemented carbide balls and an appropriate amount of acetone. The mixture was charged in a container, and the container was mounted on a ball mill to grind and mix. Then, CBN powder was added thereto, and the mixture was wet-mixed in a rotary ball mill for 72 hours. After drying, the diameter was increased at a pressure of 3 ton / cm ^2. : 20mm x thickness: 1.
It is press-molded into a green compact having a size of 5 mm, and this green compact is temporarily sintered in a vacuum of 3 × 10 ^-4 torr at a predetermined temperature in the range of 1000 to 1300 ° C. for 30 minutes. Then, it was charged into an ultra-high pressure sintering apparatus in a state of being superimposed on a WC-based cemented carbide base material having a size of diameter: 20 mm × thickness: 2 mm, at 5 GPa in the range of 1200 to 1400 ° C. Ultra-high pressure sintering under the condition of holding at a predetermined temperature for 30 minutes, grinding the upper and lower surfaces, dividing into four by wire cutting, brazing to a WC base cemented carbide base metal, and polishing to a predetermined throw-away tip shape Cutting tools made of the CBN-based ultrahigh-pressure sintered material of the present invention (hereinafter referred to as cutting tools of the present invention) 1 to 15 having substantially the same component composition as the finishing, and comparative CB
Cutting tools (hereinafter, referred to as comparative cutting tools) 1 to 8 made of an N-based ultrahigh-pressure sintered material were manufactured, respectively.

[0009] The comparative cutting tools 1 to 8 are dispersed among the constituents of the CBN-based ultra-high pressure sintering material, especially the Ti carbon / nitride, and affect the wear resistance. , AlN, TiB ₂ , or Al ₂
The content of O ₃ (marked with * in Table 2) has a composition outside the scope of the present invention.

[0010] Next, for the cutting tools 1 to 15 of the present invention and the comparative cutting tools 1 to 8 obtained as a result, a work material: a round bar of FCD70 (spheroidal graphite cast iron), a cutting speed: 400 m / min. 0.25mm, feed: 0.2mm / rev. , Time: 20 minutes, wet continuous continuous high-speed cutting test of cast iron, and work material: carburized hardened round bar of SCM415, cutting speed: 300 m / min., Depth of cut: 0.1 mm, feed: 0.1 mm / Rev. A dry continuous high-speed cutting test of steel was performed under the following conditions: time: 20 minutes, and the flank wear width of the cutting edge was measured in each test. The results of these measurements are shown in Tables 1 and 2.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

According to the results shown in Tables 1 and 2, the cutting tools 1 to 15 according to the present invention show that the CBN-based ultra-high pressure sintered material constituting the Fine WC, AlN, TiB ₂ and Al with the following particle sizes
₂ O ₃ has a dispersed structure and exhibits excellent wear resistance in high-speed cutting, while the WC, AlN, TiB ₂ , and Al ₂ O
It is clear that any content of any of the _three out of the range of the present invention results in poor wear resistance.
As described above, the cutting tool made of a CBN-based ultra-high pressure sintered material of the present invention exhibits excellent wear resistance not only in ordinary cutting but also particularly in high-speed cutting, and exhibits excellent cutting performance over a long period of time. You do it.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-20437 (JP, A) JP-A-1-119564 (JP, A) JP-A-5-17233 (JP, A) JP-A-4-199 240006 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23B 27/14 C04B 35/58 103

Claims (1)

(57) [Claims] The present invention provides a binder phase forming component comprising: 20 to 40% of Ti carbon / nitride comprising one or more of Ti carbides, nitrides, and carbonitrides; 0.1 to 2%, aluminum nitride: 1 to 5%, titanium boride: 3 to 7%, aluminum oxide: 5 to 15%, and the remainder is inevitable with cubic boron nitride as a dispersed phase forming component. Having a composition of impurities (more than volume%),
And a cubic boron nitride-based ultra-high pressure having a structure in which a binder phase has a structure in which tungsten carbide, aluminum nitride, titanium boride, and aluminum oxide, each having a particle size of 0.5 μm or less, are dispersed and distributed on a Ti carbon / nitride base material. A cutting tool made of a cubic boron nitride-based ultra-high pressure sintered material having excellent wear resistance, comprising a sintered material.