JPS6023180B2 - Sintered material for cutting tools with excellent high-temperature properties and its manufacturing method - Google Patents

Description

Detailed Description of the Invention The present invention provides a competitive material that has excellent high-temperature properties and exhibits excellent cutting performance when used as a cutting tool for high-speed cutting or high-feed cutting that particularly requires high-temperature properties. and its manufacturing method.

Generally, when cutting steel, when the cutting speed is increased or the feed rate is increased, the temperature of the cutting tool's cutting edge increases, and the cutting tool's useful life is shortened due to plastic deformation caused by high temperatures rather than wear. In many cases, these days,
It is becoming increasingly stronger due to high-speed cutting and high-efficiency cutting in recent years.

However, in the superalloys and cermets currently in practical use, in which the dispersed phase is mainly composed of W carbide or Ti carbide, and the binder phase is mainly composed of iron group metals, when the cutting edge temperature exceeds 1000°C, In order to soften rapidly, not only these superalloys and cermets, but also surface-coated cemented carbides and surface-coated cermets with a hard coating layer formed on their surfaces must be used under conditions where the cutting edge temperature is high. The temperature is limited to slightly above 1000°C. On the other hand, ceramics whose main component is A oxide exhibits high hardness and excellent oxidation resistance at high temperatures.
Although it is put into practical use as a cutting tool for high-speed cutting,
Since the cutting edge lacks wear resistance and is insufficiently reliable, it is currently used at a low feed rate during high-speed cutting. In addition, in recent years, cast alloys having a structure in which W and Ti carbides are dispersed in a layered structure in a matrix consisting of a high melting point metal such as W or Mo (for example, the U.S. patent No. 3,690,962) was proposed and attracted attention, but this cast alloy has a significantly high melting point of 2,700°C, and since it is a cast alloy, it is not only difficult to shape it, but also has poor oxidation resistance and Since impact resistance is also insufficient, it has not been widely put into practical use.

Therefore, from the above-mentioned viewpoint, the present inventors have developed a material for cutting tools that has excellent high-temperature properties that enable high-speed cutting and high-feed cutting, that is, wear resistance, plastic deformation resistance, oxidation resistance, and As a result of research to manufacture cutting tools with excellent impact resistance using powder metallurgy, we found that as a raw material powder,
Metal carbide powder, metal nitride powder, metal carbonitride powder,
Ni-A alloy powder and W powder are prepared, two or more of these raw material powders are blended into a predetermined composition, mixed under normal conditions, press-formed, and then pressed into the resulting material. The powder was heated in a non-oxidizing atmosphere at a temperature of 2,000 to 2
After sintering at a high temperature of 700 qo, that is, the complete solidification temperature, it is cooled from the above-mentioned grilled mackerel temperature in a non-oxidizing atmosphere.
A compound precipitation treatment is performed at a predetermined temperature within the temperature range of 000 to 1600°C for a predetermined time, and Ti: 5
~25%, one or two of Zr and Hf: 5~
20%, one or two of Nd and Ta: 5~
20%, Ni: 0-5~3-0%, A〆;○-5~2-
0% (Aso/Ni: 0.25-0.5), C315-4
0%, N: 1 to 15%, the remainder is W and unavoidable impurities (however, W: 20 to 55%), and the dispersed phase is mainly composed of Ti, C, and N. It consists of a fine hard phase consisting of a compound phase consisting of a compound phase mainly composed of one or two of Zr and m, and C and N, while a binder phase consists of a Ni-A intermetallic compound and a W W whose main component is
When a competitive alloy with a structure consisting of a base alloy is manufactured,
The resulting material has excellent wear resistance, plastic deformation resistance, oxidation resistance, and impact resistance. They obtained the knowledge that when used as a cutting tool for high-speed cutting or high-feed cutting that requires these high-temperature properties, it exhibits extremely excellent cutting performance.

This invention has been made based on the above knowledge, and the reason why the composition range of the material and the dawning temperature are limited as described above will be explained below.

[a-TiTi component forms a compound phase mainly composed of Ti, C, and N that is dispersed in the matrix as a fine hard phase, imparting high hardness to the material, thereby improving the wear resistance of the material. However, if the content is less than 5%, the desired amount of the compound cannot be precipitated in the compound precipitation treatment during the cooling process from the intermelted state in the silk burning process, and as a result, the desired wear resistance cannot be achieved. On the other hand, if the content exceeds 25%, the amount of the compound phase forming the dispersed phase becomes too large compared to the binder phase, and the impact resistance of the material deteriorates. Therefore, its content was determined to be 5 to 25%.

[b} Zr and Hr Similar to Ti, both of these components are mainly composed of one or two of Zr and Hf, C and N, and form a compound phase that is dispersed as a fine hard phase in the matrix. However, if its content is less than 5%, it will not be possible to secure the same high hardness as Ti, that is, high wear resistance.On the other hand, if its content exceeds 20% Similarly, if the compound phase is allowed to increase, the amount of the compound phase forming the dispersed phase increases too much, and the impact resistance of the material deteriorates. Therefore, the content was set at 5 to 20%.

'c) Nb and Ta These two components have the effect of diffusing into the above two compound phases and solidifying into the substrate to improve the oxidation resistance of the material, but their content is less than 5%. However, if the content exceeds 20%, the wear resistance of the material decreases, so the content was set at 5 to 20%.

'd-Ni and AZ These two components not only improve the competitiveness of W, which constitutes the binder phase, but also form an intermetallic compound consisting of Ni3A, and combine the compound phase and binder phase, which constitute the dispersed phase. It has the effect of improving the bonding strength of the material, thereby significantly improving the impact resistance of the material, but if the content is less than 0.5% for Ni and 0.5% for A, the desired effect may not be achieved. On the other hand, if the content exceeds Ni: 3.0% and A〆: 2.0%, the wear resistance of the material will decrease. 3.0% and A
So: Set at 0.5-2.0%.

{e) C As mentioned above, the C component has the effect of forming two types of compound phases to improve the wear resistance of the material, but if its content is less than 15%, the amount of the hard dispersed phase becomes relatively small. If the content is too small, it is not possible to secure the desired wear resistance, while if the content exceeds 40%, the ratio of the compound phase to the binder phase becomes too large, leading to deterioration of the impact resistance of the material. Therefore, the content was determined to be 15 to 40%.

'f) The NN component has the effect of making the above compound phase finer and further improving the impact resistance of the material, but if its content is less than 1%, the desired impact resistance cannot be secured; On the other hand, if the content exceeds 15%, the amount of N decomposed during marriage will increase and voids will be formed in the material, resulting in deterioration of impact resistance. was set at 1 to 15%.

[g} W A part of the W component diffuses into the above compound phase, but
Most of the remaining portion constitutes the binder phase of the base material, and this binder phase consists of the components constituting the above-mentioned dispersed phase, as well as a W-based alloy in which Ni and A are melted, so the material has excellent plastic deformation resistance. , and impact resistance.

However, if the content is less than 20%, the amount of the binder phase is relatively too small, resulting in particularly poor impact resistance, while if the content exceeds 55%, the amount of the dispersed phase is relatively small. If the amount is too low, the wear resistance of the material will deteriorate, so the content is set at 20 to 55%. The fired material of the present invention contains Fe,
Co, Cr, Mo, Si, and platinum group metals (Pt, P
Even if it contains one or more of the following: d, Rh, Ru, lr, 0s), as long as the total content is 2% or less, the properties of this dawn material will not be impaired in any way. do not have.

(h) At the competitive sintering temperature of 2000 qo, the structure during brining does not become a complete solid solution, and as a result, in the compound precipitation treatment process after sintering, a fine hard compound phase is uniformly formed on the W-based alloy base. Since it is not possible to obtain a structure in which the particles are dispersed, it is not possible to secure the desired wear resistance and impact resistance.On the other hand, when the sintering temperature exceeds 2700°C, a liquid phase appears. Since it becomes difficult to maintain the shape, the sintering temperature should be set at 2000~
It was set at 2700 qo.

{i} Compound precipitation treatment temperature If the temperature is less than 1000°C, the amount of compounds separated by analysis will be too small, making it impossible to obtain a structure in which fine hard compounds are uniformly dispersed, and as a result, the material will have poor wear resistance. On the other hand, even if the temperature exceeds 1600°C, the same amount of compounds and intermetallic compounds cannot be separated, so the temperature is set at 1000~1600°C. Established.

Although the material for cutting tools of the present invention can be used alone, it can be used in combination with one or two of Ni and A as binder phase forming components: 25-6
0%, also one or two of Mo and W: 5
~20%, and the remainder consists of one or more carbides and nitrides of metals from the umbrella, tortoise, and road groups of the periodic table as hard dispersed phase-forming components and unaccumulated impurities ( or more atomic %), and in this state, for example, in a vacuum of 10-2 tons, hold at a temperature of 1370 qo for 3 minutes to bond the two, and use it as a composite material. In this case, the impact resistance will further increase.

In addition, carbides, nitrides, and oxides of metals from the umbrella, string, and candy groups of the periodic table, as well as their Two or more types of solid ports, further aluminum oxide (hereinafter referred to as A〆203), zirconium oxide (hereinafter referred to as Zr02)
It shows even better oxidation resistance when used in a state where it is coated with a hard coating layer consisting of one type of single layer or two or more types of multilayers with an average layer thickness of 0.5 to 15 mm. It becomes like this.

Next, the dawning material of the present invention and its manufacturing method will be specifically explained with reference to Examples.

Example 1 TIC having an average particle size of 1.0 mm as a raw material powder
Powder, 1.2 m of (Tio.58Wo.42) C powder, 1.5 m of ZrC powder, 1.0 m of (Tio.58Wo.42)
HfM5N body. 55) C powder, TaC powder of 1.2 mm, TIN powder of 1.5 m, Ni- of 1.7 m
A-alloy (A-so: 31.5% by weight content) powder, A-so 2.5
Prepare a Ni powder of 1.2 mm and a W powder of 1.2 mm, combine two or more of these raw material powders to a predetermined composition, wet mix in a ball mill for 7 hours, and dry. After that, it is press-molded at a pressure of 15k9/Iso to form a green compact, and then this green compact is heated in an air stream twice a day at a temperature of 80℃.
After pre-sintering by holding at qo for 1 hour, sintering was performed at a temperature of 260030 for 1 hour in a vacuum of 10-1 rr, and after competitive sintering, the sintering temperature was 1500oo
By cooling at a cooling rate of 700q0/hr over a temperature range up to and Hisame Sintered Materials 1 to 7 were produced, respectively.

In addition, Comparative Cadder Materials 1 to 7 all have the content of one of the constituent components (those marked with * in Table 1).
has a composition outside the scope of this invention.

Next, a cutting tip having a shape of SNP432 was prepared from each of the resulting Akatsuki materials 1 to 6 of the present invention and Comparative Akatsuki alloys 1 to 7, and the work material was JIS/SN.
CM-8 (hardness: HB260), cutting speed: 230m'
min, feed: 0.4 ribs/rev. Continuous high-speed cutting test under conditions of depth of cut: 2 ribs, cutting time: 10 minutes, work material: JIS/SNCM-8 (hardness: HB280), cutting speed: 14 discs/min, feed: 0.275 ribs , depth of cut:
On the 2nd side, an interrupted cutting test was conducted under the conditions of cutting time: 3 minutes, and in the continuous high-speed cutting test, the flank wear depth and crater wear depth on the chip cutting edge were measured, and in the interrupted cutting test, the number of tested cutting edges was measured. The number of chipped cutting edges out of 10 was measured.

These measurement results are also shown in Table 2. In addition, the first
For comparison purposes, the table shows a ceramic cutting tip mainly composed of A-oxide, and a Ti carbide (TIC) formed by chemical depositing on the surface of a cemented carbide substrate mainly composed of W carbide.
) and A〆oxide (A-203) with a total average layer thickness of 7 m, cutting test results of surface-coated cemented carbide cutting tips (referred to as conventional cutting tips 1 to 2) under the same conditions are also reported. Indicated. As is clear from the results shown in Table 1, conventional cutting tip 1 had particularly poor impact resistance, resulting in damage to all of the test cutting edges, and conventional cutting tip 2 had excellent impact resistance. Although it shows excellent cutting performance equivalent to that of the composite material of the present invention in an interrupted cutting test, it suffers from a large amount of wear in a continuous high-speed cutting test due to inferior wear resistance.

On the other hand, it is clear that the sintered materials 1 to 6 of the present invention exhibit excellent cutting performance in both intermittent and continuous high-speed cutting tests. Furthermore, Hisame sintered material 1~
As seen in No. 7, if the content of any of the components deviates from the range of the present invention, the cutting test result will be poor in at least one of the continuous cutting test and the intermittent cutting test. Example 2 In addition to the raw material powder used in Example 1, the average particle size:
1.2 French m (Tio.58Wo.42) Co. 95 powder, and 1.0 lm of TICo. 5N.

After preparing the powder powder and blending these raw material powders into a predetermined composition by appropriately combining them, mixing this blended powder under the same conditions as in Example 1, press molding, and further pre-sintering. , in a vacuum of 10-2tom, temperature: 21
After solidification, the temperature range from the sintering temperature that maintains the solid solution structure to 1200°C was cooled at a cooling rate of 700°C/hr.
By performing a compound precipitation treatment under the condition of holding at 200 ° C. for 5 hours, the brazed materials 7 to 10 of the present invention having the component compositions shown in Table 2, and the content of any of the constituent components ( Bisame sintered materials 8 to 13 whose compositions (marked with * in Table 2) are outside the scope of this invention
were manufactured respectively. Next to the ship, cutting chips with the shape of SNP432 were prepared from the above-mentioned composite materials 7 to 10 of the present invention and Hisame sintered materials 8 to 1, 3, respectively, and the work material was JIS/SNCM-8 (
Hardness: HB250), Cutting speed: 115: m/min,
Feedback: 0.8mm rev. A continuous high-feed cutting test was conducted under the following conditions: depth of cut: 5 skins, cutting time: IQ minutes, flank wear depth and crater wear depth were measured, workpiece material: SNCM-8 (hardness HB280), cutting speed. :10
0m'min, feed: 0.3 side/rev. , depth of cut: 2
Sail, cutting time: Conducted an intermittent cutting test under the conditions of 3 minutes, 1
The number of missing edges among the cutting edges of the hardened steel was measured.

The measurement results are shown in Table 2. Table 2 also shows, for comparison purposes, a hard layer of Ti carbide coated with an average layer thickness of 6 rm by chemical vapor deposition on the surface of a commercially available cemented carbide substrate mainly composed of W carbide. surface-coated cemented carbide cutting tips consisting of P30 W carbide as a main component (hereinafter referred to as conventional cutting tips 3 and 4).
The results of cutting tests under the same conditions are also shown.

As shown in Table 2, the results of the same machine in Example 1 are shown, and the cutting tips made with the sintered materials 7 to 10 of the present invention are all the conventional cutting tips 3 and 4 and the Bisame sintered alloy. It is clear that the cutting tips exhibited much better cutting performance than the cutting tips prepared in Nos. 8 to 13.

Example 3 The sintered material 8 of the present invention produced in Example 2 was polished into a cutting chip having a shape of SNP523, and the cutting chip was made of Ti(C) having an average grain size of 2.0 mm.
O. 7NO. 3) Powder, Mo powder of 0.8 mountain m, 2
．． Using Ni powder of 5 mm and Ni-A alloy (containing 31.5% A) of 1.7 mm as raw material powders, Ti(C) was produced.

．． 7N. ．． 3): 45%, Mo: 10%, Ni: 43%
, A: Blend to a composition of 2% (at least atomic %), wet mix in a ball mill for 6 hours, dry, and then produce 15k9
/Produced by press-forming with the pressure of a fence to obtain a green compact, holding this green compact in a 10-ton vacuum at a temperature of 1400°C for 1 hour to sinter, and then polishing. It was stacked on a cermet chip having a final component composition substantially the same as the above-mentioned composition and having a shape of SNP523, and held in this state at a temperature of 1370 qo in a vacuum of 10-4 tom for 30 minutes. Both were joined. The resulting composite cutting tip of the present invention was applied to workpiece material: JIS/SNCM-8 (hardness: HB260), cutting speed: 12 h'min, feed: 0.8 m/rev, depth of cut: 5 Continuous high-feed cutting test under conditions of cutting time: 10 minutes, and work material: JIS/SNCM-8 (hardness:
HB280), cutting speed: 120m/mjn, feed: 0
．． 35 side/rev. When subjected to an interrupted cutting test under the conditions of depth of cut: 3 ribs and cutting time: 3 minutes, in the continuous high feed cutting test, the flank wear depth on the chip cutting edge was 0.
13 ribs, the same crater wear depth: 30 mm, and in the intermittent cutting test, out of the number of cutting edges tested, no cutting edges were damaged.

Example 4 Using the cutting tip of the sintered material 2 of the invention produced in Example 1, inserting the cutting tip into a known chemical vapor deposition layer,
The surface was first treated under the following conditions: reaction temperature: 1020°C, reaction gas composition: 2:96%, TIC: 4:2%, C ratio: 2% (or more by volume %), and reaction time: 150 minutes. Coated with TIC having an average layer thickness of 6 fm, then at the same temperature, Q: 96%, TIC 4: 2%, CH4: 1.95%
, CO: 0.05% (volume % or more) by flowing a reaction gas for 1M minutes to form a Ti(CMO) layer with an average layer thickness of 11m.

．． 3), and then, after completely removing the residual gas, reaction temperature: 100,000, reaction gas composition: ratio: 93%, A, C, 3: 3%, C: 4% (capacity or more). %), reaction time: 100 minutes, average layer thickness:
1 meter of A-203 was coated. The resulting three-layer coated tip of the present invention was subjected to a continuous high-speed cutting test and an interrupted cutting test under the same cutting conditions as in Example 1. In the continuous high-speed cutting test, flank wear on the chip cutting edge was Depth: 0.08 skin, same crater wear depth: 10 m
In addition, in the intermittent high-speed cutting test, only one chip out of one cutting edge was damaged.

As described above, according to the present invention, a sintered material with excellent high-temperature properties, that is, wear resistance, plastic deformation resistance, oxidation resistance, and impact resistance, is manufactured using a conventional powder metallurgy method. Therefore, when the resulting composite material is used as a cutting tool for high-speed cutting or high-feed cutting that requires the above-mentioned high-temperature properties, it exhibits extremely excellent cutting performance.

Claims (1)

[Claims] 1 Ti: 5-25%, one or two of Zr and Hf: 5-20%, one or two of Nb and Ta: 5-20%, Ni: 0.5-3.0%, Al
:0.5~2.0% (Al/Ni=0.25~0.5)
, C: 15 to 40%, N: 1 to 15%, and the remainder consists of W and unavoidable impurities (however, W: 20 to 55%), and the dispersed phase is , a fine hard phase consisting of a compound phase mainly composed of Ti, C and N, and a compound phase mainly composed of one or two of Zr and Hf and C and N; A sintered material for cutting tools having excellent high-temperature properties, characterized in that it has a structure consisting of a Ni-Al intermetallic compound and a W-based alloy containing W as a main component. 2. Prepare metal carbide powder, metal nitride powder, metal carbonitride powder, Ni-Al alloy powder, and W powder as raw material powders, and mix two or more of these raw material powders into a predetermined composition. The resulting green compact is then completely solid solution sintered in a non-oxidizing atmosphere at a high temperature of 2,000 to 2,700°C, followed by mixing and press-forming under normal conditions. Medium, temperature 1000-1600℃
Compound precipitation treatment is performed with Ti: 5 to 25%, one or two of Zr and Hf: 5 to 20%, one or two of Nb and Ta: 5 to 20%, Ni:
0.5-3.0%, Al: 0.5-2.0% (Al/N
i=0.25-0.5), C: 15-40%, N: 1-
15%, and the rest is W and unavoidable impurities (however, W:
20 to 55%) (at least atomic %), and the dispersed phase is a compound phase containing Ti, C, and N as main components, and one or two of Zr and Hf. C and N
To produce a sintered material having a microstructure consisting of a fine hard phase with a compound phase mainly composed of A method for producing a sintered material for cutting tools with excellent high-temperature properties.