JPS5915970B2 - Tough cermet with a softened surface layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cermet that has excellent toughness and is particularly suitable for use in heavy cutting such as interrupted turning and milling.

Generally, titanium carbide (hereinafter referred to as TiC) is itself brittle, so if a cermet containing TiC as a main component (TiC-based cermet) is used for heavy cutting such as interrupted turning or milling, it may cause fracture. This naturally limits its field of application.

On the other hand, since TiC has excellent oxidation resistance, heat resistance, and welding resistance, if the brittleness of the TiC-based cermet is improved and toughness is improved, it is possible to improve the ) It is clear that it will have a field of application that surpasses the WCC superalloy containing WCC as a main component.

Therefore, in order to impart toughness to the TiC-based cermet, molybdenum (MO) and MO carbide (hereinafter referred to as Mo
2C), W, WCl and Ti nitride (hereinafter referred to as Ti
Among these components, Mo, MO2C, W, and W are added.
When C is added and contained, a so-called intermediate phase is formed in which these components surround TiC, and in this double structure with TiC as the core, the components are
Since TiC is not solidly dissolved in C, the toughness of TiC itself cannot be improved, and when the added content of TiC increases, problems such as a sharp decline in the wear resistance of the cermet occur. .

Similarly, when TiN is added, the effect of suppressing the grain growth of TiC occurs, but the toughness of TiC itself cannot be improved, and furthermore, when the added content of the above component increases, Problems such as the formation of cavities and bores (small holes) in the TiC-based cermet and the decrease in the strength of the cermet occur.
o, Mo 2 parts m Even if components such as WeWCl and TiN were added, sufficient toughness could not be imparted to the cermet.

On the other hand, a T1CN-based cermet manufactured using Ti carbonitride (hereinafter referred to as T1CN) powder as the main raw material prepared by dissolving TiCKTiN in advance has also been proposed, but this cermet is also compared with a cermet containing TiN. In this case, judging from the fact that there is almost no difference in cutting performance and cermet properties, it cannot be said that the TiCN-based cermet has higher toughness than the TiN-added cermet.

Therefore, from the above-mentioned viewpoint, the present inventors conducted research to obtain a cermet with significantly improved toughness compared to conventional cermets, and as a result, (a) One or more metals of group 4a and group 5a and one or two metals of group 6a
When a compact containing as a main component one or more hard phase-forming components of composite carbides and composite carbonitrides is sintered in an appropriate nitrogen atmosphere, the nitrides in the surface layer are sintered in an appropriate nitrogen atmosphere. The components forming the surface layer are nitrided, making it difficult for the particles to form bridges, and the internal binder phase is pulled out to the surface layer, resulting in a softened surface layer with a hardness distribution that decreases continuously toward the surface. 2. A cermet having extremely high toughness is obtained.

(b) A part of the components in item (a) above may be added to 4a and 5a of the periodic table, which tend to form nitrides, as necessary.
Even if the substitution is made with one or more hard phase-forming components from the group consisting of group metal carbides, carbonitrides, composite carbides, and composite carbonitrides, the fact shown in paragraph (a) above does not apply. not be damaged at all.

(c) The cermet in item (a) above contains one or more of the group consisting of carbides of metals from group 6a of the periodic table, nitrides and composite nitrides of metals from groups 4a and 5a of the periodic table. When included as a hard phase forming component, the thickness and hardness of the softened surface layer of the cermet can be adjusted.

(d) Cr group metal (
When one or more of the following (representing Cr, Mo, and W) is contained, the Cr group metal is dissolved in the iron group metal, and the high temperature strength of the cermet is further improved. The wettability with the hard phase during sintering is further improved.

(e) When Al is included in the binder phase of the cermet, fine A7 intermetallic compounds are formed and the high temperature strength of the softened surface layer of the cermet is further improved.

The findings shown in section (a)-Je) have been obtained above.

Therefore, this invention was made based on the above knowledge, and basically uses cermet as (a) a hard phase-forming component, which is difficult to form nitrides;
Carbides of group 6a metals of the periodic table, as well as group 4a and 5 metals of the periodic table.
One or more types of nitrides and composite nitrides of group a metals (hereinafter referred to as softening surface layer adjustment component 5): 3.6 ~
48.5%, (b) Also as a hard phase forming component,
4a and 5a of the periodic table, both of which form nitrides
One or more types of composite carbides and composite carbonitrides (hereinafter referred to as softened surface layer formation Component 5) Contains 1.5 to 93.4%, and if necessary, (c) 4a and 4a of the periodic table, which are also easy to form nitrides and are also hard phase forming components. One or more of group 5a metal carbides, carbonitrides, composite carbides, and composite carbonitrides ((
Hereinafter, referred to as the softening surface layer forming substitution component 5): 3.6~
Section 48.5, (d) One or more of the Cr group metals 2-1
Section 5, (e) l: o, Section 05 to 5, containing one or more of the above (c) to (e), (f) the remainder being an iron group metal as a binder phase forming component. A composition consisting of one or more of the following and unavoidable impurities, and a hard phase: 60 to 97 parts, a binder phase: 3 to 40 parts (the above is the volume ratio, the following composition is the volume ratio) ), and the cermet has a maximum depth of 300 mm from its surface.
It has a hardness distribution that increases continuously towards the inside to μm, and the surface hardness is 5 to 20L compared to the internal hardness.
It is characterized by having a low softening surface layer.

Next, in the cermet of the present invention, the reason why the numerical values are limited as described above will be explained.

(1) Content of hard phase and binder phase If the hard phase content is less than 60%, the binder phase content will be relatively large, exceeding 40 q/), and the thickness of the softened surface layer will exceed 300 μm. If the thickness of the softened surface layer becomes thicker than 300 μm, the cermet will easily undergo plastic deformation, which is undesirable. On the other hand, if the content of the hard phase increases beyond 97 modulus, the bond will become relatively weak. Since it becomes difficult to form a softened surface layer when the phase content is less than 3 widths, the content of the hard phase was set at 60 to 97 parts, and the content of the binder phase was set to 3 to 40 parts.

(2) Content of softening surface layer adjusting components When the content of these components is less than 3.6%, the thickness of the softening surface layer becomes thicker than 300 μm, and the plastic deformation resistance of the cermet decreases. If the content exceeds 48.5%, it becomes difficult to form a softened surface layer, so the content was set at 3.6 to 48.5%.

(3) Content of softening surface layer forming components If the content of these components is less than 11.5%, it is difficult to form a softened surface layer.On the other hand, if the content exceeds 93.4'Z, the thickness of the softened surface layer will be less than 300 μm. It becomes too thick,
Since the plastic deformation resistance of the cermet decreases, its content is determined to be 11.5 to 93.4.

(4) Content of substitute components for forming a softened surface layer If the content of these components is less than 3.6%, no substitution effect will be obtained, while if the content exceeds 48.5%, the content will cause a relatively softened surface layer. If the content of the forming components becomes too small, the toughness of the cermet will deteriorate, so the content is set at 3.6 to 48.5.

(5) Content of Cr group metal If the content is less than 1%, the desired effect of improving high-temperature strength and improving wettability with the hard phase cannot be secured, whereas if the content exceeds 15%, , since the toughness of the cermet decreases, the content should be increased from 1 to 15.
%.

(6) Content of Al If this component is less than 0.05%, the desired high temperature strength cannot be obtained.On the other hand, if the content exceeds 5q/), for example, N1T
Because brittle phases such as i(Al) precipitate and reduce the toughness of the cermet, the content was reduced to 0.05%.
It was set at ~5%.

(7) Thickness of the softened surface layer If the softened surface layer becomes thicker than 300 μm, plastic deformation will easily occur in the cermet, so the thickness should be reduced to 30 μm.
It was set as 0 μm or less.

(8) Surface hardness of the softened surface layer Compared to the internal hardness of the cermet, the softening degree of the surface hardness is 5.
%, the desired toughness cannot be imparted to the cermet, and on the other hand, if the softening degree of the surface hardness is lower than 20%, the cermet becomes susceptible to plastic deformation. The hardness was set to be 5 to 20 times lower than the actual hardness.

(9) Thickness of the coating layer If the thickness is less than 1 μm, the desired effect of improving wear resistance by forming the coating layer cannot be secured;
If the thickness exceeds 100 μm, the brittleness of the coating layer will appear, and the toughness of the cermet will deteriorate due to this brittleness. Therefore, the thickness was determined to be 1 to 20 μm.

Next, the tough cermet of the present invention will be explained using examples.

Example l As a raw material powder, (Ti) with an average particle size of 1.0 μm was used.

W) CN powder (T i N / T i C / WC-20 weight ratio / 40 weight ratio 740 weight ratio), 1.5 μm Ti
c powder, 1.2 μm NbC powder, 1.2 pm W
C powder, Cr3C2 powder of 2.0 μm, TiN powder of LOpm, ZrN powder of 1.5 μm, 1.8 μm
VN powder, 2.2μm NbN powder, 2.54m
(Hf, Ta)N powder (HfN/TaN-50 weight ratio 750 weight ratio), Mo powder of 0.6 μm, 1.0
μm W powder, same LO prn Ni powder, and 1.2
Using Co powder of μm, these raw powders are blended into the composition shown in Table 1, this blended powder is pulverized and mixed in a ball mill, and then a green compact is formed from this mixed powder, and the compacted powder is The powder was stored in a vacuum at 10” oaHg at a temperature of 1
After holding the temperature at 200°C for 1 hour to perform degassing treatment, nitrogen gas was introduced, the furnace pressure was set at 5011t11LHg, the temperature was raised to 1450°C, and the furnace was evacuated at this temperature to 10-l
A cermet 1 of the present invention having substantially the same composition as the blended composition is obtained by creating a vacuum of mmHg, then continuing to flow nitrogen gas again to maintain the furnace pressure at 1OxmHg for 1 hour, and sintering. -11 and comparative cermet 1 were manufactured, respectively.

Note that Comparative Cermet) 1 has a softening surface layer adjusting component content outside the range of the present invention.

In addition, for the purpose of comparison, it has the composition shown in Table 1,
However, a comparative cermet 2 was produced that did not have a softened surface layer.

Next, the above-mentioned cermets 1 to 11 of the present invention. Comparative cermets 1 and 2, and a commercially available cermet without a softened surface layer, which is conventionally known as a material for cutting tools (hereinafter referred to as conventional alloy 1).
) to Cl5 (Cemented Carbide Tool Association Standard)/SNMN
Cutting test chips with shapes conforming to 432 were manufactured, and workpiece material: JIS-8NCM-8 (hardness HB: 270), Chitsubu Honing Ni 0.03rIL, cutting speed: 120 m/min, feed. An interrupted cutting test was conducted under the following conditions: 0.4 mm/rev, depth of cut = 2.0 length, cutting time: 30 m1n, and the number of missing cutting edges among the 10 test cutting edges was measured.

These results are shown in Table 1, which also shows the thickness of the softened surface layer, hardness distribution, softening rate of surface hardness relative to internal hardness, and internal hardness. .

Further, FIG. 1 shows the hardness distribution of the cermet 1 of the present invention and the comparative cermet 1.

As is clear from the results shown in Table 1, the cermets 1 to 11 of the present invention having the softened surface layer defined by the present invention are:
It was confirmed that both showed superior interrupted cutting characteristics compared to Comparative Cermets 1 and 2 and Conventional Alloy 1, and had high toughness.

Example 2 As a raw material powder, (T 1sNb with an average particle size of 1.5 μm)
, W) C powder (TiC/NbCA red-40 weight ratio/40
weight%/20 weight ratio), Zr powder of 1.5μ7W, VC powder of 2.0pm, Mo2C powder of 1.2μm,
1.2 μm TaN powder, 0.6 pm Mo powder,
Same 1.0 μm Cr powder, Same i.

Using Ni powder with a diameter of 1.2 μm and Fe powder with a diameter of 1.2 μm, these raw material powders are blended into the composition shown in Table 2, this blended powder is pulverized and mixed in a ball mill, and then from this mixed powder A green compact is molded, and the green compact is heated to 10
After degassing by holding the temperature at 1200℃ for 1 hour in a vacuum of miHg, nitrogen gas was introduced and the furnace pressure was increased to 300miHg.
The temperature was raised to 1450'C as Hg, and at this temperature it was evacuated to create a vacuum of 10-lmmHg, and nitrogen gas was continued to flow again to make the furnace pressure 300miHg, which was held for 1 hour to sinter and substantially Cermets 12 to 14 of the present invention having the same composition as the blended composition were manufactured.

For the purpose of comparison, Comparative Cermet 3 has a component composition defined in the present invention by changing the above sintering conditions, but the depth of the softened layer is deep outside the range of the present invention, and Comparative Cermet 3 has a similar composition. Comparative cermet 4 was produced, which was within the range of the present invention, but whose softening rate of the surface hardness of the softening layer exceeded the range of the present invention.

Next, the same materials as in Example 1 were prepared from cermets 12 to 14 of the present invention, comparative cermets 3 and 4, and cemented carbide P30 (hereinafter referred to as conventional alloy 2) without a softened surface layer, which is conventionally known as a material for cutting tools. Cutting test chips were manufactured under the following conditions: Work material: JIS-8NCM-8 (Hardness HB: 270), Chip honing: 0.03 Ho, Cutting speed: 80 m/min, Feed 20, 5 Dragon 1 rev. An interrupted cutting test was conducted under the following conditions: depth of cut: 2.0 m, hot cutting time: 3.0 m1n, and the number of missing cutting edges was measured in the same manner as in the example work.

The results are shown in Table 3 together with the mode of the softened surface layer.

Further, FIG. 2 shows the hardness distribution of the cermet 12 of the present invention and the comparative cermet 3.4.

As shown in Table 3, the cermets 12 to 14 of the present invention
has extremely superior cutting properties compared to Comparative Cermets 3 and 4, which were all rendered unusable due to plastic deformation because the softened surface layer was outside the range defined in the present invention, and the conventional alloy (P2O). That is, it is clear that it has toughness.

Example 3 As a raw material powder, (T isT
a*Zr*W) CN powder (TiC/Ti
c/T a C/Z r C/WC-zs4/ in weight width
30%/10'Z/1%/34%), 1.5μm
(Ti.

W) C powder (TiC/WC=50 weight ratio 150 weight qb
), 1.5 p ml) Ti CN powder (TiC/
TiN - weight width 20%/80%), same 2.0 μm Z
rCN powder (ZrC/ZrN - weight range 20%/80%
), 1.8 pm VcN powder (VC/VN-weight range: 304/7096), 1.5 μm TaCN powder (T
aC/TaN=3OL:l)/70% by weight), 12 μm WC powder, 0.6 pm Mo powder, 1.
0 μm Ni powder, 1.5 μm (Ti, Ta) C powder (TiC/TaC = so4/zoqb by weight), 2.0 pm (T 1 #Nb) C powder (TiC/Nb
C = 70 coefficient / 3096), 2.2 μm (T
isTa) CN powder (TiC, TiC/TiN-40%/40%/20% in weight range), 2.5 pm N1-A
Example 1 except that d alloy powder was used, these raw material powders were blended into the composition shown in Table 4, and the furnace pressure created by the continuous flow of nitrogen gas in the final sintering step was set to 50 mHg. Cermet 1 of the present invention having substantially the same composition as the compounding composition under the same conditions as in
5 to 28 were produced, respectively.

Next, Example 2 regarding the cermets 15 to 23 of the present invention
An interrupted cutting test was conducted under the same conditions as in , and the results are shown in Section 4 along with the appearance of the softened surface layer.

As shown in Table 4, the cermets 15 to 28 of the present invention
It is clear that both have excellent toughness.

Example 4 As a raw material powder, (Ti) with an average particle size of 1.0 μm was used.

W) C powder (TiC/WC=30 weight ratio/70 weight ratio)
, TaC powder of 1.5 μm, WC powder of 3.5 μm, and Co powder of 1.2 μm. Molecular aC220q (softening surface layer formation amount: hard phase) conversion component) wc230 (softening surface layer adjusting component) Co:15 (binding phase) The powder mixture is pulverized and mixed in a ball mill, and then a green compact is formed from the mixed powder. Degas treatment by holding at a temperature of 1200°C for 1 hour in a Hg vacuum.
After that, nitrogen gas was introduced, the pressure inside the furnace was set to 150iiHg, the temperature was raised to 1450°C, the temperature was evacuated at this temperature, and the furnace was heated for 10
The cermet 29 of the present invention has substantially the same composition as the compounded composition by creating a vacuum of "miHg" and then continuing to flow nitrogen gas to maintain the furnace pressure at 150 Hg for 1 hour and sintering. A chip for a cutting test was manufactured from the resulting cermet 29 of the present invention under the same conditions as in Example 1, and then the cutting edge was coated with 01
After honing to a thickness of -03 mm, a chemical vapor deposition method was applied to produce (a) the present invention cermet 29A with a TiC coating layer having an average layer thickness of 7 μm on the surface, and (b) a TiN coating layer also having an average layer thickness of 5 μm. (c) A cermet 29B of the present invention in which a T1CN coating layer with an average layer thickness of 5 μm was formed, and a cermet 29C of the present invention in which an Al2O3 coating layer with a flat layer thickness of 1 μm was formed on this coating layer were manufactured.

For comparison purposes, the conventional cemented carbide P20 (hereinafter referred to as conventional alloy 3) which does not have a softened surface layer and the conventional alloy 3
A commercially available coated cemented carbide with a TiC coating layer formed on the surface of (
A tip with the same cutting edge shape was manufactured from conventional alloy 4).

Next, regarding the cermets of the present invention) 29A to 29C and the conventional alloy 3.4, (1) Interrupted turning conditions Work material: JIS-8NCM-8 (hardness HB 2270)
), 0.03 mm.

Cutting speed: 100 m/min, Delivery 20.4/rev.

Depth of cut: 2. Omm.

Cutting time = 3.0 m in, (2) Continuous turning conditions Work material: JIS-3NCM-8 (Hardness HB: 220), Chitsubu Honing Ni 0.03 m, Cutting speed = 150 m/min, Feed 20.3 mml rev,, Cutting depth: 1.
5. Intermittent cutting tests and continuous cutting tests were conducted under the conditions of cutting time = 10.0 m1n, and in the interrupted cutting tests, toughness was evaluated by measuring the percentage of cutting edge defects, and in the continuous cutting tests, the toughness was evaluated by measuring the percentage of cutting edge defects. Wear resistance was evaluated by measuring the flank wear width and rake face wear depth of the blade.

The results are shown in Table 5 together with the mode of the softened surface layer.

As shown in Table 5, the present invention cermets 29A-2
It is clear that 9C has superior toughness and wear resistance compared to conventional alloys 3 and 4.

Example 5 As a raw material powder, (Ti) with an average particle size of 1.2 μm was used.

Mo) C powder (T i C/Mo2C-50 weight ratio 15
0 weight ratio), Tin powder of the same LOpm, WC powder of the same 1.2pm, Mo powder of the same 0.6μm, and the same i.

Using 1.0 μm Ni powder and 1.0 μm Co powder, the composition of the cermet was changed to (Ti, Mo)C250% (softening surface layer forming component) (hard phase) wc215'il'' ( Softening surface layer adjustment J component) TiN: 15% Mo2 10% Ni: 5% Co: 5% Binding phase Co: 5% In addition, the furnace pressure μ after degassing in the sintering process and the furnace pressure during final sintering were adjusted to 1100 m 1 H. The cermet 3 of the present invention was prepared under the same conditions as in Example 4 except that the composition was substantially the same as that of the compounded composition.
0 was manufactured, and a cutting edge was also manufactured from this, and the ion blating method was applied thereto to form (a) a T i CN coating layer with an average layer thickness of 8 μm, (b) the cermet 30A of the present invention; A cermet 30B of the present invention having an HfC coating layer having a layer thickness of 5 μm and (c) a cermet 30C of the present invention having an HfN coating layer having an average layer thickness of 5 μm were manufactured.

Next, regarding the cermets of the present invention) 30A to 30C and the conventional cemented carbide PIO without a softened surface layer (hereinafter referred to as conventional alloy 5), cutting speed: 150 m/min, feed:
0.3 mvt/rev, Example 4 except that
An interrupted cutting test was conducted under the same interrupted turning conditions as in Example 4, and a continuous cutting test was conducted under the same continuous turning conditions as in Example 4, except that the cutting speed was 200 m/min. It is shown in Table 6 together with the aspects.

As shown in Table 6, in this example, Example 4
The results were similar to those of the present invention thermets) 30A.
It is clear that ~30C has excellent toughness and wear resistance.

As mentioned above, the cermet of the present invention has extremely excellent toughness, so it is excellent when applied to high-load cutting such as interrupted cutting and milling, which conventional cermets and WCC cemented carbide were not good at. It has industrially useful properties such as excellent cutting performance and excellent properties against friction and wear, so it can be applied to wear-resistant parts.

[Brief explanation of the drawing]

FIGS. 1 and 2 are curve diagrams showing the hardness distribution of the cermet of the present invention, the comparative cermet, and the conventional alloy.

Claims (1)

[Scope of Claims] 1. As a hard phase forming component, one of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of metals of group 4a and 5a of the periodic table, all of which are difficult to form nitrides. species or two or more species = ratio 3.6 to 48.5; also as a hard phase forming component, one or two or more metals from Groups 4a and 5a of the periodic table, both of which form nitrides; Composite carbides with one or more of the group 6a metals and one or more of composite carbonitrides: 11.5 to 93.4, and the remainder forms a binder phase. A cermet consisting of one or more iron group metals as components and unavoidable impurities, and having a composition (capacity range above) consisting of: a hard phase of 260 to 97 parts, and a binder phase of 3 to 40 parts. Further, the cermet has a maximum depth of 2300 μm from its surface.
A tough cermet having a softened surface layer, which has a hardness distribution that continuously increases toward the inside, and has a surface hardness that is 5 to 20 orders of magnitude lower than the internal hardness. 2. As a hard phase forming component, one or more of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of metals of group 4a and 5a of the periodic table, all of which are difficult to form nitrides: Sections 3.6 to 48.5, also as hard phase-forming components, one or more of the metals of group 4a and 5a of the periodic table, both of which form nitrides, and the metals of group 6a of the periodic table. Composite carbides with one or more of these and one or more of composite carbonitrides: Sections 11.5 to 93.4, both of which are easy to form nitrides as hard phase forming components. , one or more of carbides, carbonitrides, composite carbides, and composite carbonitrides of group 4a and 5a metals of the periodic table = ratio 3.6 to 48.5, and the remainder is A composition consisting of one or more iron group metals as binder phase forming components and unavoidable impurities, and consisting of a hard phase of 260 to 97 parts and a binder phase of 23 to 40 parts (capacity range above) Further, the cermet has a maximum depth of 2300 μm from its surface.
A tough cermet having a softened surface layer, which has a hardness distribution that continuously increases toward the inside, and has a surface hardness that is 5 to 20 orders of magnitude lower than the internal hardness. 3. As a hard phase forming component, one or more of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of metals of group 4a and 5a of the periodic table, all of which are difficult to form nitrides. Sections 3.6 to 48.5, also as hard phase-forming components, one or more of the metals of group 4a and 5a of the periodic table, both of which form nitrides, and the metals of group 6a of the periodic table. One or more of composite carbides and composite carbonitrides with one or more of: Sections 11.5 to 93.4, one or more of the Cr group metals as a binder phase forming component 2 or more types = coefficient 1 to 15, the remainder consists of one or more iron group metals as bonding phase forming components and unavoidable impurities, and hard phase: ratio 60 to 97, bonding The cermet has a composition (capacity range above) of phase: 3 to 40, and further, the cermet has a maximum depth of 2,300 μm from its surface.
A tough cermet having a softened surface layer, which has a hardness distribution that continuously increases toward the inside in V, and has a softened surface layer whose surface hardness is 5 to 20 orders of magnitude lower than the internal hardness. 4. One or two types of hard phase-forming components, carbides of group 6a metals of the periodic table, nitrides and composite nitrides of group 4a and 5a metals, all of which are difficult to form nitrides. Above: Sections 3, 6 to 48.5, also as hard phase-forming components, one or more metals of Groups 4a and 5a of the periodic table, both of which form nitrides, and metals of Group 6a of the periodic table. A7il: 0.05-5 as a binder phase forming component; , and the remainder consists of one or more iron group metals as binder phase forming components and unavoidable impurities, and hard phase: 60 to 97, binder phase: 3 to 40 ai), Further, the cermet has a composition (capacity ql) consisting of:
A tough cermet having a softened surface layer, which has a hardness distribution that increases continuously toward the inside at t, and has a softened surface layer whose surface hardness is 5 to 20 orders of magnitude lower than the internal hardness. 5 As a hard phase forming component, one or more of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of metals of group 4a and 5a of the periodic table, all of which are difficult to form nitrides. Sections 3.6 to 48.5, also as hard phase-forming components, one or more metals from groups 4ak and 5a of the periodic table, all of which form nitrides, and metals from group 6a of the periodic table. Composite carbides with one or more of these and one or more of composite carbonitrides: Sections 11.5 to 93.4, both of which are easy to form nitrides as hard phase forming components. , one or more of carbides, carbonitrides, composite carbides, and composite carbonitrides of group 4a and 5a metals of the periodic table: 3.6 to 48.5, as a binder phase forming component, one or more Cr group metals: 1 to 15, the remainder consisting of one or more iron group metals as a binder phase forming component and unavoidable impurities, and A cermet having a composition (capacity range above) consisting of a hard phase of 260-97% and a binder phase of 3-40%, and further, the cermet has a maximum depth of 2300 μm from its surface.
A tough cermet having a softened surface layer, which has a hardness distribution that continuously increases toward the inside, and further has a softened surface layer whose surface hardness is 5 to 20% lower than the internal hardness. 6. As a hard phase-forming component, one or more of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of group 4a and 5a metals, all of which are difficult to form nitrides: Sections 3.6 to 48.5, also as hard phase-forming components, one or more of the metals of groups 48 and 5a of the periodic table, which form nitrides, and the metals of group 6a of the periodic table. Composite carbides with one or more of the following and one or more of the composite carbonitrides in Sections 211.5 to 93.4, both of which tend to form nitrides as hard phase forming components. , one or more of carbides, carbonitrides, composite carbides, and composite carbonitrides of group 4a and 5a metals of the periodic table: 3.6 to 48.5, as a binder phase forming component, Contains 0.05 to 5% Al2, and the remainder is one of the iron group metals as a binder phase forming component.
The cermet is made of one or more species and unavoidable impurities, and has a composition (capacity range above) consisting of: hard phase: 60-97%, binder phase: 3-40%; Maximum depth of 2300μm from the surface
A tough cermet having a softened surface layer, which has a hardness that continuously increases toward the inside, and further has a softened surface layer whose surface hardness is 5 to 20 orders of magnitude lower than the internal hardness. 7. As hard phase-forming components, carbides of group 6a metals of the periodic table, which are difficult to form nitrides, and 4a of the periodic table.
One or more of nitrides and composite nitrides of group 5a and group 5a metals: Sections 3.6 to 48.5, also as hard phase forming components, all of which form nitrides, listed in the periodic table. One or more composite carbides and composite carbonitrides of one or more metals from Groups 4a and 5a and one or more metals from Group 6a 211. 5 to 93.4, as a bonding phase forming component, one or more of the Cr group metals 21 to 15; also as a bonding phase forming component, containing 120.05 to 5; However, the remainder consists of one or more iron group metals as binder phase forming components and unavoidable impurities,
and a cermet having a composition (capacity width) consisting of: hard phase: 60 to 97 parts; binder phase: 3 to 40 parts; and further, the cermet has a maximum depth of 300 μm from its surface.
' = 1 and has a hardness distribution that increases continuously toward the inside, and is characterized by having a softened surface layer whose surface hardness is 5 to 20 orders of magnitude lower than the internal hardness. cermet. 8. As a hard phase forming component, one or more of carbides of group 6a metals of the periodic table, nitrides and composite nitrides of metals of group 4a and 5a of the periodic table, all of which are difficult to form nitrides: Sections 3.6 to 48.5, also as hard phase-forming components, one or more of the metals of group 4a and 5a of the periodic table, both of which form nitrides, and the metals of group 6a of the periodic table. or one or more of composite carbides and composite carbonitrides: ii, s ~ 93.4q/), both of which are easy to form nitrides as hard phase forming components. , one or more of carbides, carbonitrides, composite carbides, and composite carbonitrides of group 4a and 5a metals of the periodic table = coefficient 3.6 to 48.5, as a binder phase forming component, Contains one or more of Cr group metals: 1 to 15, Al2O, 05 to 5 as a bonding phase forming component, and the remainder is an iron group metal as a bonding phase forming component. A cermet comprising one or more of the above and unavoidable impurities, and having a composition (capacity range above) consisting of: a hard phase (260 to 97 dl), and a bonding phase (23 to 40 dl). The maximum depth of the cermet above is 300 μm from the surface.
1. A tough cermet having a softened surface layer, which has a hardness distribution that continuously increases toward the inside at i, and has a softened surface layer whose surface hardness is 5 to 20 orders of magnitude lower than the internal hardness. □