JPH02254131A - Nitrogen-containing cermet having excellent various characteristics, its manufacture and coated nitrogen-containing cermet - Google Patents

Abstract

PURPOSE:To manufacture the cermet having excellent various characteristics suitable to a material for a cutting tool or the like by forming a nitrogen-contg. cermet having specified compsn. from a bonding phase essentially consisting of Co and a hard phase essentially consisting of a cored structure constituted of a titanium carbide core part and a conjugate carbon nitride circumferential part. CONSTITUTION:The nitrogen-contg. cermet is formed from a bonding phase essentially consisting of Co and/or Ni and a hard phase of which the core part is constituted of titanium carbide or titanium carbon nitride and the outer circumferential part surrounding the core part is constituted of a cored structure of (Ti-M) (C-N) [M denotes at least one kind among Ta, Nb, W and Mo, or at least one kind among Ta, Nb, W and Mo and at least one kind among Zr, Hf and V]. Furthermore, the compsn. of the cermet is constituted of, by weight, 7 to 20% Co and/or Ni, 35 to 60% Ti, 4 to 25% Ta and/or Nb, 9 to 30% W and/or Mo, 0.1 to 2% Zr and/or Hf, 0.3 to 7% V, 3 to 9.5% N and 4 to 12% C with inevitable impurities.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a hard cored structure in which the core is made of titanium carbide or butane carbonitride, and the outer peripheral part surrounding the core is made of composite carbonitride. Concerning the nitrogen-containing cermet mainly containing phase, specifically, for example, turning I tool, milling L tool,
Cutting of drills, end mills, etc. - Materials for wear-resistant upper materials including tools such as Gutagawa materials or slitters, cutting blades or molds for cans, or decoration of cases, brooches, tie bottles, etc. The present invention relates to a nitrogen-containing cermet with excellent properties suitable as a material for industrial use, a method for producing the same, and nitrogen-containing cermets 1 to 1.

(Prior art) In general, N-free T having the basic composition of l'1c-Ni
For example, when used as feed for cutting tools, iC-based sert has the advantage of being excellent in flank wear resistance when cutting steel, but has the disadvantage of being significantly inferior in chipping resistance. Because of this, there is a problem that it can only be put to practical use in applications where there is very little impulsive force. An N-containing TiC-based cermet whose basic composition is TiCTiN-Ni is an attempt to solve the problem of N-free r i C) and (cermets).

N-containing A・1 rICIC-met is N-free r
IC base salt: By adding TiN, Ti (C, Ni, etc.) as a composite carbonitride containing gold elements, grain growth of the hard phase is suppressed, resulting in increased strength. We have achieved this goal.

This N-containing TiC-based cermet has N-free rI
Although it has been able to achieve a certain degree of improvement in strength compared to C-based Zamet, when used as a cutting tool material, it still cannot be said to have sufficient strength depending on the cutting conditions, and conversely, N-free However, there is a problem in that it also reduces the abrasion resistance, which is the advantage of TiC-based Sammet.

Many such N-containing [IC-based cermets] have been proposed to solve the problem, and a representative example is Japanese Patent Publication No. 57-21019.

(Problems to be Solved by the Invention) Japanese Patent Publication No. 1983-Z+O+Q2 discloses that Zr carbide and/or carbide 0.2 to 5.0 wj%, Mo, Mo
carbide.

One or two of W and W carbide 10.0~
300w%, 11 nitride 10.0-25. Owt%
, and the rest is T' a carbide and/or N
75 to 95 wt% of a hard phase consisting of a composite carbide substituted with a carbide, part or all of which is dissolved in the TI carbide, and inevitable impurities, one or two of iron group metals;
A sintered hard alloy comprising 5 to 25 wt% of a binder phase comprising a pusher is disclosed. The sintered hard alloy disclosed in the publication has the following characteristics: ``A conventional N-containing TiC-based cermet containing IN suppresses grain growth of IC due to preferential solid solution of TiN into the binder phase. Although it is effective, it does not solve the problem that riN dissolves with ``)C during sintering and does not improve the strength of TiC, and furthermore, as the added content h1 of TiN increases, the wear resistance deteriorates. T, T
High toughness and excellent wear resistance are achieved by adding Zr carbide and/or V carbide, which form a solid solution with iC, and by forming a composite carbide made by dissolving Ta carbide and/or Nb carbide in riC. Although it is an excellent hard alloy that enables high-speed cutting, N-free TiC-based shark metal has better wear resistance in the high-speed cutting range, and can only be used in the medium- to low-speed cutting range. The problem is that the practical area is narrow.

The present invention solves problems such as the following: specifically, impregnation with Zr and/or IIF and ,
The presence of a hard phase with a cored structure made of composite carbonitride and a -L body surrounding the core provides abrasion resistance of 1 strength and wear resistance and plastic deformation resistance at high temperatures. Nitrogen-containing thermets I with excellent properties such as properties
The object of the present invention is to provide a method for manufacturing the same, and a coated nitrogen-containing cermet obtained by coating the surface of a nitrogen-containing cermet with a film.

(Means for Solving the Problems) The present inventors have improved various properties of N-containing cermets.
We were considering expanding the practical area, especially the Tenkawa area as a cutting tool material, and extending its life. First, we decided to add ZrC, 1Irc, and VC to the N-containing cermet.
When N-containing cermet is added, it becomes a solid solution in both the hard phase and the binder phase. t': + Improves temperature plastic deformability! - to cause, or 7. rC, 1lrc, and VC tend to be more easily dissolved in the hard phase with Tic as L than in the binder phase,
This improves the high temperature plastic deformability of the hard bound phase. However, even if the high-temperature plastic deformation resistance of the hard phase is improved, when N-containing cermet is used as a cutting tool material, the tool tip temperature is estimated to be at most 100°C, and this temperature range is However, if the plastic deformation resistance of the hard phase is made to be the same, the toughness of the tool will be reduced. This is because the binder phase is much more easily plastically deformed than the hard phase, and if there is a large difference in the respective plastic deformation resistances of the binder phase and the hard phase, the plasticity of the binder phase will deteriorate in the initial stage of cutting. Deformation occurs, cutting resistance increases and chips occur regardless of the plastic deformation resistance of the hard phase. Furthermore, since the deformation behavior of the alloy at about 1100° C. is largely due to the deformation of the binder phase, it is essential to further strengthen the binder phase. Therefore, the added ZrC, 1lfc, VC
found that a larger amount of force dissolved in the binder phase than in the hard phase can improve high temperature plastic deformation resistance without impairing the toughness of the alloy.

Second, N-containing cermets include ZrC, 1Irc, and VC.
ZrC-VC, 1 l compared to the case of adding ip,
When added in combination with rc-VC or ZrC-11rc-VC, the amount of solid solution in the hard phase decreases dramatically,
We have obtained the knowledge that a correspondingly large amount of solid solution is dissolved in the bonded phase.

Thirdly, the hard phase is T i C or r i (C, NI
If it is made of particles of Ill, the strength of the particles themselves is low, and if it is made of particles of composite carbide, in which carbide is solid-solved in IIC, the strength of I'/Li itself is 4", but the wear resistance is low. 11C or Ti (
C, N) as a core, and the outer periphery surrounding this core is made of a composite carbonitride of T1 and other metals, the [i
It has been found that C or Ti (C, Nl) improves wear resistance, and composite carbonitride at the outer periphery improves strength.

The first of these. The present invention was completed based on the second and third findings.

That is, the nitrogen-containing cermet of the present invention having excellent properties has Co and/or Ni: 7 to 20 wt% and '1
: 35-60 wt% and '21 and/or Nb: 4
~25wt% and W and/or Mo: 9~30w1;
% and 7. r and/or 11[・0, l~2wj% and V
: 0.3 to 7 wt% and N (nitrogen): 3 to 9.5 wt%
and C (carbon): 4 to 12 wt%; The hard phase has a core made of titanium carbide or titanium carbonitride, and an outer peripheral part surrounding the core made of (Ti).
, Ml (C, Nl [([+, M is l'a, N
b, W, Mn (all 1 type, or Ta,
At least one of Nb, W, Mo and 7, r
It does not represent at least one species of IllV. It is characterized by mainly having a cored structure consisting of .

The binder phase in the nitrogen-containing cermet with excellent properties of the present invention is CO or Ni, or Co and N.
i and other elements that form a hard phase therein, such as W, Mo, Ti, Zr, IH
.

It is preferable that at least one of Ta, Nb, and V, especially χ'' and/or 11'', and V are dissolved in a fine solid solution. Fe, Cr, etc. may be dissolved in solid solution1
゜The hard phase in the nitrogen-containing cermet with excellent properties of the present invention is a core of titanium carbide or titanium carbonitride (Ti
, M) Mainly have a core structure surrounded by a composite carbonitride of (C,N).To give a more specific example, a core of titanium carbide is surrounded by a core of (Fi, M,
) fc, N) [Ran 1, Ml is Ta, Nb,
7. at least one species of WMo; r, llf,
5. Representing at least one type of V. ] The core of the first hard phase titanium dicarbide of the J core 1114 structure is surrounded by the outer periphery of the composite carbonitride of (Ti, M=) (C, N)
[However, M2 represents at least one of TaNb, W, and Mo jl,] A second hard phase with a cored structure surrounded by the outer periphery of the composite carbonitride, a core of titanium carbonitride; The 33rd hard phase has a cored structure surrounded by the outer periphery of the composite carbonitride of (Ti, Ll (C, Nl), and the core of titanium carbonitride is surrounded by the composite carbon of (Ti, M2) fc, N). A fourth hard phase with a 1-core structure surrounded by the outer periphery of nitride; 5th hard phase with a J-core structure surrounded by the outer periphery of titanium carbonitride, which is a titanium nitride core; 6th hard phase of titanium nitride without core structure, (Ti, M,) 7th hard phase of +i1 of (C, N), (Ti, M21 fc, N
9, among these hard phases, those with an iron core structure of the first to fourth hard phases contain 50% or more of the total hard phase. If the hard phase of this cored structure contains more than 90% of the total hard phase, the various properties of the alloy such as wear resistance 9 strength and high temperature plastic deformation resistance f1 will be improved. 1. When these hard phases exist in the sintered body, the form is that if it consists of the first hard phase, the first hard phase and the second to eighth hard phases The phase may consist of at least IN!, the third hard phase, or the third hard phase and at least one of the second, fourth, and eighth hard phases. be.

Among the compositional components of the nitrogen-containing cermet with excellent properties of the present invention, if CO and/or Ni is less than 7wt%, the toughness will be significantly deteriorated, and conversely, if it exceeds 20wt%, the wear resistance will deteriorate. Co and/or Ni is set at 7 wt % to 20 wt % because the deterioration in properties is serious.

Among the other compositional components, 11 forms the core and outer periphery of the cored structure as 1E, and when 11 is less than 35W%, the wear resistance decreases significantly due to the decrease in the core, and vice versa. r
When i increases beyond 60 w%, the deterioration of the rice layer becomes significant because the pores containing other components become relatively small, and Zr and/or IIF and , the effect of combined addition of Zr and/or 11 [and
1. Since deformability also deteriorates, Ti is 35 to 60 wt%.
This is what has been established. "2] and/or old] and W and/
or M(+ means Ij′ which forms the outer periphery of the hard phase with a core structure and approaches the toughness direction 1″, especially “a and/or N
b increases the strength at high temperatures, and W and/or Nb increase the wettability with the binder phase, making the strength closer to each other.The former is less than 4w11% and the latter is less than 9wt%. When this happens, the strength deteriorates significantly, and conversely, the 111I person loses 2
If the amount exceeds 5wt% and the latter is 30w%
If the number exceeds , the relative content of i
decreases and the wear resistance becomes worse.
and/or Nb is 4 to 25w1. %, W and/or M(
] is determined to be 99 to 30wt. Due to the combination of Zr and/or IH and (), these are dissolved in both the outer periphery and the binder phase, and moreover, they are dissolved in the binder phase in a larger amount than before. It contributes to the improvement of plastic f1 deformability, high-temperature strength, and wear resistance.If Zr and/or 11[ is less than 0wt% and V is less than 03%, the effect becomes extremely weak. Conversely, Zr and/or 11
If [[] exceeds 2wt% or [■] exceeds 7wt%, the sinterability becomes low, making it difficult to form a dense sintered body, and as a result, the strength also decreases. Since Zr and/or II f tends to decrease, Zr and/or II f is 0.1 to
2 wt%, and ■ is determined to be 0.3 to 7 wt%.

In addition, when N content is less than 3wt%, it only lowers the wear resistance and has no effect on the toughness of the sintered body.
If the content is less than t%, it is difficult to form a sufficiently dense sintered body, so the N content is set at 3 to 9.5 wt%.

The unavoidable impurities in the nitrogen-containing cermet of the present invention, which have excellent properties, include: (1) impurities contained as emitting substances, and (1) impurities that are mixed in during the manufacturing process. Among these, (1) mixing of emitting substances during mixing and crushing, for example!・
C, Mn, and Cr mean that the amount of admixture from the conventional manufacturing process is within the range of 1/r volume, and there are also unavoidable impurities that remain in the sintered body due to the double edge of the starting material and manufacturing process. There is oxygen as It is particularly preferable that the amount of oxygen remaining in the sintered body is 0.7 WL% or less.

The nitrogen-containing cermet of the present invention, which has excellent properties, can be produced by the conventional powder metallurgy method, but it is easy to produce a hard phase with a cored structure in the sintered body. In addition, it is preferable to carry out the method described in 11 because denitrification in the sintered body can be prevented and the morphology of the hard phase can be easily controlled since it contains 1 nitrogen and 1 carbon. .

That is, a nitrogen-containing reamer having excellent properties according to the present invention
The method for producing So1- consists of Co and/or Ni powder, carbide powder, nitride powder of metals of groups 4a, 5a, and 6a of the periodic table, and at least one of these mutually isosoluble powders.
A manufacturing method for obtaining a nitrogen-containing cermet by blending, mixing, drying, molding and sintering using a scale,
The sintering process was performed in a 71' fan vacuum up to 1350°C, with a nitrogen atmosphere of I Lorr at 1350°C;
From 1350°C to the sintering holding temperature, the nitrogen content LL was gradually increased with #1jA, and at the sintering holding temperature, it was 5 Lorr.
This is the J method (manufacturing method), which is characterized by creating a nitrogen atmosphere.

CO and/or Ni powder in the method for producing nitrogen-containing Zamet with excellent various properties of the present invention, and Periodic Table 4a
, 5a, 6a group metal carbide powders, nitride powders, and mutually isosoluble powders thereof. It is preferable to use powders that are as uniform and finely grained as possible, for example, with a skewer average particle size of 5μ.
Powders having an average particle diameter of m or less, preferably i, Iε, 3 μm or less are preferred. In addition, each of the 11 steps of blending, mixing, drying, and molding in the method of manufacturing a nitrogen-containing cermet with excellent properties according to the present invention can be performed using the methods used in conventional powder metallurgy. It is something. In the method of manufacturing a nitrogen-containing cermet with excellent properties according to the present invention, the vacuum environment means, for example, 10-'Lor
r -IQ-'Lorr, and the sintering holding temperature is the temperature at which shrinkage is completed, for example, 1450°C to 1550°C,
The temperature must be maintained at the temperature described in step 1 for 30 to 90 minutes.

The nitrogen-containing cermet having excellent properties of the present invention is used as a base material, and the surface of this base material is coated with a conventional physical vapor deposition method (PVD method) or chemical vapor deposition method fCV.
method), a hard film with higher hardness than this base material, specifically, for example, carbides, nitrides, carbonates, nitride oxides of metals in group 4aba and fia of the periodic table, and their phases LI
, solid solutions as well as silicon nitride, silicon carbide, aluminum oxide UNO\, aluminum nitride: -Rum, oxynitride aluminum UNO 1.
By coating with a film consisting of at least one tit layer or multi-Φ layer among boron nitride and daruya nitride, a coated nitrogen-containing cermet has even better wear resistance. This is desirable.

The coated nitrogen-containing cermet of the present invention is produced by: 1) After sintering is completed at the holding temperature of the sintering method in the manufacturing method described in 11, it is further held in a high nitrogen pressure atmosphere for a certain period of time to form a nitride film. By forming a film on the surface of the base material, ■ - the culm can be simplified, the interface between the hard film and the base material is not affected by impurities, and the need for equipment for CVD and I'VD methods is eliminated. This is preferable because there is no such thing. The thickness of this coated nitrogen-containing cermet film needs to be selected depending on the material, purpose, and shape of the film, and is approximately 0.
A thickness of 1 to 10 μm is practical, a thickness of 01 to 5 μm is preferable when impact resistance is desired, and a thickness of 3 to 1 Jtm is preferable when abrasion resistance is desired.

(Function) The nitrogen-containing cermet with excellent properties of the present invention is
Titanium carbide or titanium carbonitride that makes up the core of the core structure acts to improve wear resistance, and makes up the outer periphery of the cored structure (Ti, M) (C, N) The composite carbonitride acts to improve the strength, and the combined effect of Zr and/or 11F and (2) improves high temperature plastic deformation resistance. In addition, Ta and/or Nb present in the outer periphery of the one-core structure has the effect of improving strength at high temperatures,
W and/or Mo serve to enhance wettability with the binder phase and to promote uniform refinement of the hard phase.

(Example) Example 1 Commercially available tic, Ti(C,N), TiN, WC,
Mo2C, 1'aCNbC, ZrC, 1lfc, VC
, (Ti, Ni))C(Ti:Nb=9:1
1, Ni, Co powder (average particle size is 1.0 to 3
g m powder) as a starting material, these starting materials were blended into the composition shown in Table 1, this blended powder was mixed and ground in a wet ball mill, paraffin was added, and after drying, press molding, and paraffin volatilization. , heated to 1350°C in vacuum, set to I Lorr nitrogen atmosphere at 1350°C,
The nitrogen partial pressure was gradually increased as the temperature was raised from 350°C to 1500°C, and the sintering temperature was held at 1500°C for 1 hour to obtain products 1 to 5 of the present invention and comparative products 1 to 5.

Furthermore, as a comparison, the steps up to the paraffin volatilization described in 1-1 were the same as those of the present invention, and the sintering process was carried out in a vacuum at 1500°C for 1 hour.
Comparative product 6 was obtained by holding for a period of time.

Table 2 shows the composition of the sintered bodies of the invention products 1 to 5 and comparative products 1 to 6 thus obtained, and the morphology of the hard phase examined using a scanning type r microscope and a light microscope. Each sample in Table 2 was given a Vickers hardness of +71 to determine its hardness and fracture toughness, and its transverse rupture strength was also measured, and the results are shown in Table 3.

Next, using each sample shown in Table 3, the following ri
d (Al, conduct cutting tests of (B) and (C),
The results are also listed in Table 3.

(A) Continuous turning test (flank wear resistance test) work material
548C Cutting speed 250 m/min Feed 0.3 mm/rev depth of cut) 1
1.5 mm Chip shape 5PGN 120308 (honing 0.1X-30°) Evaluation Measured on uniform flank wear after 5 min cutting (BL Intermittent turning test (fracture resistance test) Work material 3
48C (4 slots) cutting speed 100 m
/min 0.2 mm/rev Depth of cut -1.5 mm Chip shape 5PGN +20308 (Honing 0.1X -30°) Number of impacts until fracture or chipping (4 times ゛I dead balance) (Plastic deformation resistance test) SNCM439 80 m/m1n 0.39 mm/rev 1.5 mm 5PGN 120308 (Honing 0.1X-30°) Flank side cutting edge deformation h1 measurement after 5 minutes cutting Feed evaluation evaluation (C1 continuous turning test Work material cutting Speed Feed Depth of Cut Chip Shape F Margin Example 2 1500 from the formulation of the invention products 1 to 5 produced in Example 1
The manufacturing conditions up to °0 were almost the same as in Example 1, and 150
Nitrogen atmosphere of 20 Lorr at 0℃, 1 at 1500℃
After holding for a period of time, it was cooled at a rate of 50° C./min to obtain inventive products 1 to 5 of Example 1 as inventive products 6 to 10, respectively. 6～
When the surface portions of Sample No. 10 were examined by scanning electron microscopy and X-ray analysis, it was found that a TiN coating of about 1 to 1.3 gm was formed on 1 inch of each surface of Products No. 6 to No. 10 of the present invention.

Using these invention products 6 to 10, the cutting tests (A), (B), and (C) performed in Example 1 were conducted, and the results are shown in Table 4.

1 Margin (Effects of the Invention) As is clear from the examples below, Ratio 1 and 4 which deviate from the present invention have low hardness and low tactile resistance at 1100°C, and have low wear resistance. Comparative product 2.3, which tends to have inferior deformation resistance and is out of the scope of the present invention, has a fracture toughness value of 1 and a chamber temperature. i1! Conventional N
Comparative product 5.6, which is a cermet containing cermet, has low hardness, transverse rupture strength at room temperature, and transverse rupture strength at 1100°C, and tends to have poor abrasion resistance and deformation resistance. Nitrogen-containing cermets have excellent properties such as hardness, fracture toughness,
The transverse rupture strength at room temperature and the transverse rupture strength at 1100℃ tend to be high in a well-balanced manner, and the abrasion resistance, deformation resistance, and impact resistance are significantly superior compared to these comparative products. There is.

In addition, the method for producing nitrogen-containing zamet with excellent properties according to the present invention can denitrify even cermet with a high nitrogen content, which has been considered difficult to sinter and difficult to obtain a dense sintered body. This has the effect of making it possible to form a dense sintered body.

Furthermore, the coated nitrogen-containing cermet of the present invention has the same properties as the nitrogen-containing cermet of the present invention, which has excellent deformation resistance and impact resistance of the roadway,

Claims (3)

[Claims] (1) Co and/or Ni: 7 to 20 wt% and Ti: 3
5 to 60 wt% and Ta and/or Nb: 4 to 25 wt%
and W and/or Mo: 9 to 30 wt%, Zr and/or Hf: 0.1 to 2 wt%, V: 0.3 to 7 wt%, and N (
Nitrogen): 3 to 9.5 wt% and C (carbon): 4 to 12 wt%
% and unavoidable impurities, the nitrogen-containing cermet consists of a binder phase mainly composed of Co and/or Ni, and a hard phase, the hard phase having a core made of titanium carbide or carbon. It is made of titanium nitride, and the outer periphery surrounding the core is (Ti, M) (C, N) [where M is T
at least one of a, Nb, W, Mo, or T
at least one of a, Nb, W, Mo and Zr, Hf
, V. A nitrogen-containing cermet with excellent properties characterized by its main structure consisting of: (2) Co and/or Ni powder and periodic table 4a, 5a
, a manufacturing method for obtaining a nitrogen-containing cermet through blending, mixing, drying, molding, and sintering steps using carbide powder, nitride powder, and mutual solid solution powder of a group 6a metal. , the sintering process is at 1350℃
The temperature was raised in vacuum to 1350°C in a nitrogen atmosphere of 1 torr, and the nitrogen partial pressure was gradually increased as the temperature was raised from 1350°C to the sintering holding temperature.
rr nitrogen atmosphere, and the nitrogen-containing cermet is Co
and/or Ni: 7-20wt% and Ti: 35-60w
t% and Ta and/or Nb: 4 to 25 wt% and W and/or
Or Mo: 9 to 30 wt% and Zr and/or Hf: 0.
1 to 2 wt%, V: 0.3 to 7 wt%, and N (nitrogen): 3
~9.5 wt%, C (carbon): 4~12 wt%, and unavoidable impurities, and the nitrogen-containing cermet consists of a binder phase mainly composed of Co and/or Ni, and a hard phase, and the hard phase The core of the phase is made of titanium carbide and/or titanium carbonitride, and the outer periphery surrounding the core is (Ti, M).
(C, N) [However, M is at least one of Ta, Nb, W, and Mo, or at least one of Ta, Nb, W, and Mo and at least one of Zr, Hr, and V. represents. ] A method for producing a nitrogen-containing cermet with excellent properties, characterized in that it mainly has a cored structure. (3) A coated nitrogen-containing cermet, characterized in that the nitrogen-containing cermet having excellent properties as described in claim 1 is used as a base material, and the surface of the base material is coated with a film.