DE3211047A1 - PREFERRED BONDED, CEMENTED CARBIDE BODY AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Description

PRINCE, BUNKE &. PARTNER patent attorneys · European patent attorneys ■ "

Munich Stuttgart ■ - - '.- * ...

-1k-

KENNAMETAL INC. March 24, 198

P.O. Box 231

Latrobe, Pennsylvania 15650 /V.St.A. Our reference: K 1102

Cemented carbide bodies, preferably enriched with binder, and processes for their manufacture

The invention relates to cemented carbide bodies which, as binders, are cobalt, nickel, iron or their alloys contain, as well as the manufacture of these bodies. The invention particularly relates to metal cutting inserts made of cemented carbide with a hard, high melting point Oxide, nitride, boride or carbide coating on their surface.

Heretofore, the surfaces of cemented carbide cutting inserts have been made with a variety of hard, refractory provided coatings to improve the durability of the cutting edge and thereby the life of the insert, i.e. to extend the time during which the insert can actually be used for cutting (cf. e.g. U.S. Patents 4,035,541, 3,564,683, 3,616,506, 3,882,581, 3,914,473, 3,736,107, 3,967,035, 3,955,038; 3,836,392; and U.S. Reissue Patent 29,420. These known refractory coatings can

but regrettably the toughness of the cemented carbide inserts decrease to varying degrees. That The extent of the degradation depends, at least in part, on the structure and composition of the coating and the process that was used to deposit it. Although high-melting coatings increase the durability of Having improved metal cutting inserts, they still don't reduce the cutting edge's susceptibility to damage reduced by chipping or breakage, especially in applications where cutting is intermittent is carried out.

Previous efforts to improve the toughness or edge strength of coated, with coated cutting inserts always revolved around the production of a layer enriched with cobalt, which extends inwardly from the interface between the substrate and the coating. It was found that an accumulation of cobalt in the surface layers in

™ certain substrates with a porosity of type C is achieved when cycling through vacuum sintering processes. These areas enriched with cobalt were characterized by a type A porosity !, while the majority of the substrate was predominantly one ** Has type C porosity. Usually was in the with Cobalt-enriched zones show a depletion of solid carbide solution to different depths and to different degrees Extent to be recorded. The cobalt enrichment is desirable because it is known that the increase in de - cobalt

content increases the toughness or impact resistance of cemented carbides. Unfortunately, it's difficult to do that To control the extent of the enrichment achieved in substrates with a porosity of type C. For example, a Coating of cobalt and carbon on the user surface

of the substrate. This coating made of cobalt and Carbon was before - ". ^ M deposition of the highest .'-> melting Material on the substrate removed to form a tightly adherent

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To achieve connection between the coating and the substrate. Occasionally the extent of cobalt accumulation was in the layers below the surface of the Substrate so high that there are just opposite, ** detrimental effects on the durability of the lateral Boundary surfaces (flanks) resulted. As a result, the cobalt enriched layer was raised the lateral boundary surfaces of the substrate are sometimes ground away, so that the cobalt enrichment only increases the rake faces and the possibility of material with type C porosity the lateral boundary surface. Compared to substrates with a porosity of type A or B, substrates with a porosity of type C are chemically not so homogeneous. This can result in less control over the formation of the eta phase (a hard and brittle phase, which affects the toughness) at the interface between coating and substrate, a reduction in the Adhesion of the coating and an increase in the uneven

moderate coating growth.

By definition, the porosity of cemented carbides is classified according to three categories recommended by the ASTM (American Society for Testing and Materials) as follows:

Type A for pore sizes with diameters of less than 10 / in;

Type B for pore sizes with diameters between 10 and 40 Aim;

Type C for irregular pores caused by the presence of carbon inclusions. These inclusions are extracted from the sample during metallographic production.

pulled, leaving the aforementioned irregular pores behind.

The observed porosity can, in addition to the above classification, be a number between 1 and 6 assigned to indicate the extent or the frequency of the detected porosity. The method, according to which this classification is made is described in: Dr. P. Schwarzkopf and Dr. R. Kieffer, Cemented Carbides, McMillan Co., New York, pp. 116-120 (1960).

Cemented carbides can also be classified according to their content of carbon and tungsten binders. Tungsten carbide-cobalt alloys with an excess of carbon are characterized by type C porosity, which, as already mentioned, is formed by inclusions of free carbon. Tungsten carbide-cobalt alloys having a low carbon content, in which the cobalt is saturated with tungsten, _t are characterized by the presence of eta "phase, a M ₁₂ C or MgC carbide, wherein M represents cobalt and tungsten. Between the extremes of C-type porosity and eta-phase there is a range of intermediate compositions of binding alloy that contain tungsten and carbon in different amounts in solution, but with neither free carbon nor eta-phase present. The tungsten content in tungsten carbide-cobalt alloys can also be characterized by the magnetic saturation of the binder alloy, since the magnetic saturation of the cobalt alloy is a function of its composition. According to the literature has saturated carbon with cobalt a magnetic saturation of 15 i Gaußcm / g cobalt and suggests a porosity of Ty _t C out while a magnetic saturation of 125 Gaußcm / g cobalt, and including for the presence of eta-phase indicating .

"" The present invention is therefore to provide an easily controllable and economic ^ \ rfahrens for producing an enriched with binder layer near the surface of a cemented carbide

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Material or body made from it.

The invention also provides a cemented carbide body with a binder enriched layer near its surface, in which substantially all of the porosity over the entire cross-section of the body is of type A or B.

The invention further provides cemented carbide bodies with carbon contents which ranging from porosity of type C to eta phase, and with a layer enriched with binder close their outer surface.

Another object of the invention is to provide the aforesaid cemented carbide bodies of the invention to combine with a high melting point coating and to create coated cutting inserts with high durability and high toughness at the same time.

The invention is further explained on the basis of the following description:

According to the invention it has been found that a binder-enriched layer near the outer surface of a cemented carbide body can be formed using the following process:

First, a first carbide powder, a binder "powder and from the group of metals, alloys, hydrides, nitrides and carbonitrides of the transition elements, the carbides have a free energy of formation (heat of formation) that negative than that of the first carbide near the melting point of the binding

by means of, selected powdery chemical agent ground and mixed together, then a Compact of the mixed material sintered or subsequently subjected to a heat treatment,

wherein the chemical agent is at least partially converted to the corresponding carbide.

According to the invention, this method can be used for production a layer enriched with binder near or just below the outer surface of a cemented carbide body, preferably over the entire cross-section of the body has a porosity which is essentially only of type A or B. The enrichment can also be achieved in cemented carbide bodies that contain carbon, ranging from the eta phase to type C porosity

The cemented carbide bodies according to the invention have in addition, a layer underneath said layer enriched with binder, some of which Binder is depleted.

Preferably the first carbide is tungsten carbide. the

^The binding alloy is preferably cobalt, nickel, iron or their alloys, but cobalt is particularly advantageous.

The chemical agent is preferably from the group of

Hydrides, nitrides and carbonitrides of the elements of groups IV B and V B of the periodic table are selected and is preferably added in a small but effective amount, particularly advantageously in an amount of O! up to 2% by weight, based on the mass of the powder 3.

According to a particularly preferred embodiment of the invention, the chemical agent is Titanium nitride or titanium carbonitride.

Cemented carbide bodies according to the invention suggest

the outer surface of the body has a layer on that is at least partially impoverished in solid Li. 'ung located carbide. Cemented carbide bodies according to the invention also have below the stated ^

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in the form of a solid solution, the depleted layer is another layer, which is in solid Solution present carbides is enriched.

The cemented carbide bodies according to the invention have preferably a cutting edge at the point where a rake face and a lateral one meet Boundary surface, with a hard, dense, high-melting coating that adheres firmly to connected to these surfaces. The layer enriched with binding agent can be sanded off from the lateral boundary surface before coating with the cover will.

The refractory coating preferably consists of one or more layers of metal oxide, carbide, nitride, boride or carbonitride.

The precise nature of the invention will be based on the the following detailed description in conjunction with the drawing explains even more clearly, in which

Fig. 1 is a schematic cross section through an embodiment of an inventive coated metal cutting insert;

FIG. 2 is a graphic representation of characteristic degrees of cobalt enrichment which are present in a cemented carbide body

° is generated as a function of the distance (depth) from its cutting breasts;

Fig. 3 is a graph showing the change in relative concentrations of binders and

Carbides present in the form of solid solution as a function of the distance (depth) from the Cutting breasts of a sample prepared according to Example 12 is.

The aforementioned objects of the invention are achieved by heat treating a cemented carbide compact, the contains an element which a carbide with a more negative free energy of formation than tungsten carbide at increased Forms temperature which is close to or above the melting point. When it comes to the use case of the Cutting inserts, this element or chemical agents from the group of IV B and V B transition metals can be selected and from their alloys, nitrides, carbonitrides and hydrides. It was found, that the edge area of a cemented tungsten carbide body immediately adjacent material layer can and usually be enriched with binder throughout can be at least partially depleted of carbide present in the form of a solid solution, namely during sintering or reheating to a temperature above the melting point of the binding alloy lies by including additions of nitrides, hydrides and / or carbonitrides of the elements of groups IV B and V B of the periodic system in the powder feed.

During sintering, these additions of groups IV B and V B react with carbon to form carbides or Carbonitrides. These carbides or carbonitrides can be wholly or partly in the form of a solid solution with Tungsten carbide and other optionally present carbides are present. The one in the fully sintered carbide present nitrogen content is opposite that in shape a stick added to a nitride or carbonitride? ioff-

content is characteristically reduced because of these additives are unstable at elevated temperatures above and below the melting point of the binding alloy and result in at least partial volatilization of nitrogen from the sample when the sintering atmosphere

Contains a lower nitrogen concentration than its equilibrium vapor pressure ¹ . is equivalent to. In addition, when the c, - "mixing agent is added in the form of metal, alloy, or hydride, it becomes cubic

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Converted carbide, which is characteristically present together with tungsten carbide and possibly others Carbides is in the form of a solid solution. The hydrogen from any hydride added evaporates during sintering.

The metals tantalum, titanium, niobium and hafnium and their hydrides, nitrides and carbonitrides can be used alone or in Combination with each other can be used to promote a continuous cobalt enrichment through Sintering or subsequent heat treatment of alloys based on tungsten carbide-cobalt with an inside carbon content lying further limits. It was found that additions totaling up to about 15% by weight are useful. It is believed that the metals are zirconium and vanadium and its nitrides, carbonitrides and hydrides are also suitable for this purpose. In alloys with a porosity of type A and B and in low carbon alloys, contain the eta phase, the cobalt enrichment takes place without the formation of an external one Cobalt or carbon topcoat, so that in this way the need is avoided to have an excess of cobalt and carbon from the cemented carbide surfaces to be removed before the refractory coating is applied.

Additions of about 0.5 to 2% by weight, in particular additions of titanium in the form of titanium nitride or titanium carbonitride, to alloys based on tungsten carbide-cobalt are preferred. Because titanium nitride during vacuum sintering does not remain completely stable, as a result of which the nitrogen is at least partially volatilized preferably half a mole of carbon per mole of nitrogen used added to the for a

Tungsten-lean cobalt binding alloy to maintain the necessary carbon content. It was found, that the cobalt enrichment by way of heat treatment of alloys based on tungsten carbide-cobalt

runs more easily if the alloy contains a W-Co- binder (tungsten lean cobalt binder) which is lean on W.

The low-fat tungsten cobalt binder should be preferred

3 a magnetic saturation of 145 to 157 Gauss-cm / g Have cobalt. Additions of titanium nitride together with the necessary carbon additives to powder mixtures based on tungsten carbide-cobalt accelerate the formation of cobalt binding alloy with a magnetic one Saturation from 145 to 157, which is usually difficult to achieve. Although a cobalt binder alloy with a magnetic saturation of 145 to

157 Gauss-cm / g cobalt is preferred, alloys can also be enriched, the tungsten-cobalt binder alloys which are saturated in tungsten (less than 125 Gauss-cm / g cobalt).

It has been found that a cobalt enrichment layer with a layer thickness of more than 6 μm leads to a significant Improvement of the edge strength of cemented carbide inserts provided with high-melting coatings leads. Although cobalt enrichments have been achieved to a depth of 125 µm, one is with cobalt Enriched layer with a thickness of 12 to 50 / µm for the application of the coated cutting inserts preferred. The cobalt content of the cobalt-enriched layer is preferably between 150 and 150 in the case of an insert provided with a high-melting coating 300% of the mean cobalt content, measured on the surface by means of X-ray structure analysis.

It is believed that binder build-up occurs in all tungsten carbide binder-cubic carbide (i.e., tantalum, niobium, titanium, vanadium, hafnium, zirconium) alloys that do not sinter to form a continuous carbide skeleton, these alloys _for the Contain 3 wt .-% and more binder, rich η when using the method according to the invention. When applying the invention to cutting inserts, however

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a binder content of between 5 and 10% by weight cobalt and a total cubic carbide content of 20 wt% or less is preferred. Although cobalt is the preferred one As a binder, you can use nickel, iron and nickel-iron alloys and alloys of nickel instead and iron with cobalt can also be used. Other binding alloys such as nickel, cobalt or iron are also usable.

The sintering and heat treatment temperatures used to achieve binder enrichment are those for the Liquid sintering characteristic temperatures. For alloys based on cobalt these are temperatures 1285 to 1540 ° C. The sintering runs should last at least 15 minutes at the sintering temperature. The results can be further optimized by applying controlled cooling rates from the heat treatment temperatures down to a temperature below the melting point of the binding alloy. These cooling rates should be between 25 and 85 ° C / h, preferably between 40 and 70 ° C / h. The process stage of heat treatment for cutting inserts with a Cobalt binder lasts particularly advantageously 30 to 15Ο minutes at 1370 to 1500 ° C, followed by cooling to 1200 ° C at a rate of 40 to 70 ° C / h. The pressure applied during the heat treatment can vary between 1O -po ^^ up to those heightened

Pressures commonly used in the hot isostatic pressing process. The preferred pressure is

^oyj between 0.1 and 0.15 torr. If nitride or carbonitride additives are used, the vapor pressure of the nitrogen in the sintering atmosphere is preferably below its equilibrium pressure in order to allow the nitrogen to volatilize from the substrate.

Although an initial enrichment already takes place during sintering, there can be grinding stages in the manufacturing process of the metal cutting inserts the enriched zones again

remove. In such cases, a subsequent heat treatment can be used according to the above parameters to develop a new enriched layer below the outer surfaces are applied.

Binder enriched substrates for coated cutting inserts can have binder enrichments on both Have sides, both on the cutting breasts and on the flanks. However, depending on the type of use the binder enrichment on the flanks also removed but this is not necessary for optimal functioning in all cases.

The substrates enriched with binder can be used the coating techniques known to the person skilled in the art for the production of high-melting coatings will. Although the refractory coating applied may have one or more layers derived from the Group IV B and V B of the periodic table selected materials such as carbides, nitrides, borides and carbonitrides as well as oxide or oxynitride of aluminum, it has been found that a combination of good Cutting edge strength and flank durability can be achieved by combining a substrate with a according to the invention, enriched with binder layer with a coating made of:

- aluminum oxide over an inner layer of titanium carbide;

- or an inner layer of titanium car id, bound to an intermediate layer of T-can-

carbonitride bonded to an outer layer of titanium nitride;

- or titanium nitride bound to an inner

Titanium carbide layer. 35

A cemented carbide body is particularly preferred with a binder-enriched layer according to the invention in conjunction with a titanium carbide / aluminum oxide

Coating. In this case the coating should have a total thickness from 5 to 8 / µm.

In Fig. 1 is an embodiment of an inventive, coated metal cutting insert 2 drawn schematically. The insert 2 comprises a substrate in the form a cemented carbide body 12 with a binder-enriched layer 14 and a binder-depleted layer Layer 16 over the main part 18 of the substrate 12, the chemical properties of which essentially correspond to the chemical properties Properties of the original powder mixture correspond.

A layer 14 enriched with binder is located on the cutting breasts 4 of the cemented carbide body 12, the layer 14 on the lateral boundary surfaces, the flanks 6 of the body was ground off. Below the layer 14 enriched with binder, that is, in the direction Located on the inside of the body 12, there is a depleted of binder in the illustrated embodiment zone 16. This binder depleted zone 16 was found to coalesce with the binder depleted zone Layer 14 developed when cemented carbide bodies were made by the method of the present invention

will.
25th

The binder-depleted zone 16 is partially depleted of binder while it is in solid solution present carbides is enriched. The enriched layer 14 is partially present in solid solution

Carbides depleted. The substrate material of the main part is located below the binder-depleted zone 16 18th

At the point where the cutting breasts 4 and the

A cutting edge 8 is formed on flanks 6. Although the cutting edge 8 shown here is honed, the honing is the cutting edge not for all applications of the present Invention necessary. From Fig. 1 it can be seen

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] that the layer 14 enriched with binder extends into this cutting edge zone and preferably adjoins most of the honed cutting edge 8, if not the entire cutting edge 8. The one to Binder Depleted zone 16 extends to the surface of the flank 6, just below the cutting edges 8. A refractory coating 10 is attached to the outer surface of the cemented carbide body 12 firmly bonded.

• jQ These and other features of the invention are based on the the following examples are explained in detail:

example 1

A mixture containing 7000 g of powder was left for 16 hours long with a paraffin, a surfactant, a solvent, and cobalt-bonded tungsten carbide cycloids ground and mixed, in the following quantities and proportions:

10, 3 Wt% 5, 85 Wt .-% * O, 2 Wt .-% * 8th, 5 Wt% 1, 5 Wt .-% * 2 Wt% 2, 5 liter 14th Gram

Ta (C)
Ti (C)
Nb (C)

. 7000 g

Co

Ti (N) - 102.6 g WC + C to create a 2 wt% W-

98% by weight Co binding alloy __

Paraffin (Sunoco 3420) (Sun Oil Co.)

Solvent (perchlorethylene) surfactant (Ethomeen S-15) (Armor Industrial Chemical Co.)

*% By weight, based on the metal used.

There were block-shaped insert blanks with dimensions of 15.1 χ 15.1 χ 5.8 to 6.1 mm and with a pinem weight of 11.6 g compressed into tablets under a force of 8200 kg. These inserts were at 1496 ° C for 30 minutes vacuum-sintered for a long time and then under the in the oven egg. cooled under prevailing conditions. After sintering, they weighed

Inserts were 11.25 grams and were 13.26 13.26 χ 4.95 mm in size. These stakes were then achieved up to Edited by SNG4 33 standard dimensions as follows (This identification number is on the identification system for inserts developed by the American Standards Association and approved by the Cutting tool industry has been widely adopted. The international identification is: SNGN 12 04 12):

1. The top and bottom surfaces (cutting faces) of the inserts have been made to a thickness of 4.75 mm ground.

2. The inserts were heat treated for 60 minutes under a 100 micron vacuum at 1427 ° C and then cooled to 1204 C at a rate of 56 ° C / h and then below the surrounding area Cooled furnace conditions.

3. The lateral boundary surfaces (flanks) were up to a square with a side length of 12.70 mm ground and the cutting edges honed to a radius of 0.064 mm.

A titanium carbide / titanium carbonitride / titanium nitride coating was then applied to the ground inserts using the following chemical vapor deposition method (CVD) in the order listed below

of the individual steps:
30th

TABLE I.

coating

Reactions in the coating

Type temperature pressure

1. TiC 982-1025 ° C -1 atm. TiCl ₄ + CH ₄

TiC _(s) + 4HCl

H ₂ 2. TiCN 982-1025 ° C -1 atm. TiCl ₄ + CH ₄ +1 / 2N ₂ ^ TTiCN _(s) + 4HCl

3. TiN 982-1050 ° C ~ 1 atm. TiCl ₄ + 2H ₂ + 1 / 2N ₂ -> TiN _(s) + 4HCl

Along with the above inserts, inserts were made that were made from the same powder mixture but without TiN and its accompanying carbon addition. The coated coatings had the following microstructural properties Data on:

porosity

Thickness of the cobalt enriched zone

Thickness of the 3Q solid solution depleted zone

Thickness of the TiC / substrate intermediate layer, eta phase

Thickness of the coating

TiCN TiN

Example 1 Example 1 without TiN with TiN

A1 A1, B2 (not
enriched,
Bulk) no ~ 22.9 to
(just cutting
chest) no ~ 2 2 , ^c .um
(only cutting
chest) 4.6 µm 3.3 µm 5.6 µm
2, 3 'to
1, OyUm 5 pO _/ um
3.9 µm
1.0 'm

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Example 2

Green, tablet-shaped pressed inserts were prepared according to Example 1 and using the mixtures described in Example 1 ¹ with and without TiN and its accompanying carbon additions. These inserts were sintered at 1496 ° C for 30 minutes under a 25 micron vacuum and then cooled under the furnace conditions. They were honed on it (0.064 mm radius) and then CVD-coated with TiC / TiCN / TiN, according to the method shown in Table I. It should be noted that in this example the cobalt-enriched layer was on both the flanks and the cutting breasts.

The coated inserts were precisely evaluated, the following results being obtained:

porosity

Thickness of the cobalt enriched zone

Thickness of the solid solution depleted zone

Thickness of the TiC / substrate intermediate layer, eta phase

Coating thickness TiC TiCN TiN

Medium Rockwell "A" -

Hardness (material of the main part)

Example 2
without TiN

Example 2 with TiN

A-1 edges A-2 enriched A-3 inner zone

A-4 main part

none up to 22.9 um

no partial and discontinuous up to

21 ,around up to
5.9 µm 3, 3 to 2, 0, um
1.7 \ um
8.8 \ µm 1,
1 , 3 to
0 to
9 to

91, 2

91, 4

Coercive Force, Hc

138 Oersted 134 Oersted

Example 3

A mixture of the following materials along with a surfactant, a volatile binder, a solvent and 114 kg of cycloids placed in a cylindrical mill:

! WC (2-2.5 µm particle size) 15,000 g WC (4-5 µm particle size) 27,575 g

5.98 wt% TaC 2,990 g

2.6 wt% TiN, 1,300 g

6.04 wt% Co 3 020 g

0.23 wt% C (Ravin 410 - a product of 115 g Industrial Carbon Corp.)

50,000 g

The powder charge was balanced so that the total carbon content in the charge was 6.25% by weight.

revealed. The feed was mixed for 90,261 revolutions and grinding, resulting in a mean particle size of 0.90 μm. The mixture then became wet sifted, dried and placed in a hammer mill.

Compacts were made and then gm for 30 minutes at 1454 ° C.

chilled.

Sintered at 1454 C and then under furnace ambient conditions

This treatment resulted in a sintered blank with a total magnetic saturation of 117 to 21 Gauss-cm / g cobalt (measured including bulk and binder-enriched material). The microstructural Evaluation of the sintered blank resulted in eta-phase present through the entire blank; A-2 to B-3 type porosity; Thickness of the cobalt

enriched zone euwa 26.9 µm; Thickness of the solid solution depleted zone about 31.4 µm.

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Example 4

The following materials were placed in a tungsten carbide-cobalt alloy lined milling jar with an inner diameter of 190 mm and a length of 194 mm. In addition, were in the grinding container Given 17.3 kg of 3.2 mm tungsten carbide-cobalt cycloids. These materials were obtained by rotating the milling jar around its cylinder axis with 85 revolutions per '"minute for 72 hours (that's 367 200 revolutions) ground and mixed together.

Zus on mensetzung the charge

id; λ ι λ ι fim.7 _s \ TaC

NbC TiN C

Co toilet

105 g Sunoco 3420 20

This mixture was weighed so that a 2 wt .-% Tungsten - binder alloy containing 9 8 wt% cobalt

2c arises. After grinding and mixing, the mixture became sieved wet to remove oversized particles and impurities, then stirred at 9 3 ° C under a nitrogen atmosphere dried and ground in a hammer mill (J-2 Fitzmill, Pitzpatrick Co.) to form agglomerates

3Q to break up.

283 G (4.1% by weight) 205 G (3.0% by weight) 105 G (1.5% by weight) 7, 91 g (0.1% by weight) 381 G (5.5% by weight) 5946 G (85.8% by weight) 105 G Sunoco 3420 14th G Ethomeen S-15 2,500 ml Perchlorethylene

Compacts were produced with this powder and then at 1454 ° C. for 30 minutes:
conditions cooled.

sintered at 1454 ° C for 30 minutes and under ambient

The top and bottom surfaces, i.e. the cutting faces, of the insert were then ground to the final thickness. This was followed by a heat treatment

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1427 C under a TOO Micron vacuum. After 60 minutes at this temperature, the inserts were running at a speed cooled down from 56 ° C / h to 12O4 ° C and then cooled in the furnace under the ambient conditions prevailing there. The side surfaces (flanks) were then sanded so that there is a square with a side length of 12.70 mm and the cutting edges of the insert were honed to a radius of 0.064 mm. This treatment resulted in an insert substrate in which only the cutting breasts were enriched with cobalt and depleted of solid solution Zone exhibited, whereby these zones were ground away from the lateral boundary surfaces (flanks).

The inserts were then placed in a coating reactor and coated with a thin layer of titanium carbide, using the following chemical vapor deposition method. The hot one, the one containing the inserts Zone was first heated from room temperature to 900 ° C. Hydrogen gas was let in during the heating flow through the reactor at a rate of 11.55 l / min. The pressure in the reactor was on something held less than one atmosphere. The hot zone was then heated from 900 ° C to 982 ° C. During this second heating, the reactor pressure was kept at 180 torr, with a mixture of titanium tetrachloride and Hydrogen and pure hydrogen gas into the reactor at a flow rate of 15 l / min or 3 3 l / min entered. The mixtures of titanium tetrachloride and hydrogen gas were obtained by using the hydrogen gas flowed through an evaporator which kept the titanium tetrachloride at a temperature of 47 ° C. After reaching 982 ° C, methane was allowed to flow into the reactor at a rate of 2.5 l / min. Of the Pressure in the reactor was reduced to 140 torr. Under these

^ Conditions, the titanium tetrachloride reacts with methane in the presence of hydrogen to form titanium carbide on the hot surface of the insert. These conditions were maintained for 75 minutes, after which the influx of

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1Titanium tetrachloride, hydrogen and methane prevented became. The reactor was then allowed to cool, with argon flowing through the reactor at a flow rate of 1.53 l / min under a little less than one atmosphere pressure

5 streamed.

The examination of the microstructure of the finished insert showed a cobalt enriched zone extending up to 22.9 µm into the interior and a zone which was depleted in solid solution cubic carbide and was up to 19.7 to dissipate from the Cutting breasts of the substrate extended into the interior. The porosity in the enriched zone and in the remaining part of the substrate was on between A-1

15 and A-2 estimated.

Example 5

In this example the material was milled using a two stage milling process with the following feed mixed and mixed:

step I (48 9 600 Revolutions) TaH 141, 6 G (2.0 Wt .-%) TiN 136.4 q (1.9 Wt .-%) NbC 220.9 q (3.1 Wt .-%) TaC 134.3 q (1.9 Wt .-%) Co 422.6 q (5.9 Wt .-%) C. 31.2 q (0.4 Wt .-%) Ethomeen S-15 14th q Perchlorethylene 500 ml

Stage II (81 600 revolutions)

6098 140

1000

g g ml

(84.9% by weight)

WC

Sunoco 342Ο perchlorethylene

This composition was selected in such a way that a binder alloy composed of 2% by weight of W and 98% by weight of Co was produced.

The test inserts were then produced and coated with TiC in the same way as those described in Example 4 Trial blanks.

The microstructural examination of the coated inserts revealed a porosity of A-1 in both the cobalt-enriched material and the main body material Depth of about 32.1 resp.
36 to.

Example 6

The following materials were placed in a grinding jar with an inner diameter of 190 mm:

ι TaC
ι NbC

. ., _ -J TiN

7th Q1 η ( Π. 1 fipw - - *) C

► Co

h) toilet

Sunoco 3420
Ethomeen S-15
2500 ml perchlorethylene

This mixture was balanced so that a binder alloy with 2 wt .-% W and 98 wt .-% Co resulted.

Cycloids were also added to the mill. The mixture was then ground for four days. The ( amisch was in a Sigma mixer pump at 121 C under a
Partially vacuum dried, after which it was classified in the hammer mill through a 40-mesh sieve.

oc SNG433 inserts were then made using the method described in Example 4. The stakes
According to this example, however, V / are CVD-coated with a T ~ "VTiN coating. The following coating process was used:

283 G (4.1 Weight 205 G (3.0 Weight 105 G (1.5 Weight 7.91 G (0.1 Weight 381 G (5.5 Weight 5946 G (85, 8 wt 140 G 14th G

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1. TiC coating -

The samples in the coating reactor were under one Maintained vacuum of 125 torr at about 1026-1036C. Hydrogen carrier gas flowed into a TiCl. Evaporator at a rate of 44.73 l / min. The evaporator was under vacuum at a temperature of 3 3 to 35 C held. TiCl.-vapor was entrained by the H ^ carrier gas and dragged into the coating reactor. Free hydrogen and free methane flowed into the coating reactor with 19.88 or 3.98 l / min. These conditions were held for 100 minutes and resulted in one dense TiC coating that was firmly bonded to the substrate.

2. TiN co-sealing -

The flow of methane flowing into the reactor was interrupted and replaced with N ₂ , the nitrogen flowing into the reactor at a rate of 2.98 l / min. These conditions were maintained for 30 minutes and resulted in a dense TiN coating that was firmly adhered to the TiC coating.

The evaluation of the coated inserts resulted in the following Values:

Porosity A-1, through and through

Thickness of the cobalt enriched 17.0 to 37.9 µm zone ^/

on thickness of the solid solution depleted up to 32.7 µm Zone '

Thickness of the intermediate TiC / substrate up to 3.9 µm layer, eta phase

Thickness of the coating

TiC 3.9 µm

_TLN 2.6 / um

Rockwell "A" medium hardness 91.0 of the main part

Coercive Force, Hc 98 Oersted

Example 7

A material mix was made using the following two-step milling process:

In Stage I, the following materials were placed in a grinding jar along with 17.3 kg of 4.8 mm WC-Co cycloids with 181 mm inner diameter and 194 mm length, which was lined with WC-Co, given. The grinding container

was 10 revolutions per minute around its cylinder axis

te 4 rotated for 8 hours (2 44 800 revolutions).

h) Ta

I) TiH

i) C.

!>) Co

Ethomeen S-15 Sunoco 3420

1000 ml Soltrol 130 (a

Solvent)

In Stage II 6314 g (90.2 wt%) WC and 1500 ml Soltrol 130 were added, and all of the charge was added Rotates for 16 hours (81,600 revolutions). This mixture was balanced so that a binder alloy with 5 wt% W and 95 wt% Co. After milling, the mixture was sieved through 400 mesh, wet under Nitrogen dried at 93 ° C for 24 hours and placed in a hammer mill with a 40 mesh screen.

Test pieces were uniaxial at 16,400 kg total force to a size of 15.11 15.11 χ 5.28 mm (8.6 cm

specific weight).

140.8 G (2.0 Weight 72.9 G (1.0 Weight 23.52 G (0.3 Weight 458.0 G (6.5 Weight 30th G 120 G

The green test pieces described above were at 1468 ° C for 150 minutes under a vacuum of one Micron sintered. The stakes were then under them

ambient furnace conditions cooled. As a separating agent between the test boxes and the graphite boxes flake graphite was used.

] The inserts sintered in this way were on a Honed radius of 0.064 mm. The inserts were then coated with a TiC / TiCN / TiN according to the following procedure coated:

1. Inserts were placed in the reactor and the air was flowing out of the reactor using Hydrogen driven out.

2. The inserts were heated to approximately 1038 ° C with the flow of hydrogen through the reactor was maintained. The pressure in the coating reactor was kept to slightly more than one atmosphere.

3. TiC coating :

A mixture of H2 + TiCl2 entered the reactor at a rate of about 92 l / min and methane at a rate of 3.1 l / min for 25 minutes. The TiCl ^ -Evaporator was maintained at about 6 psi and 30 ⁰ C.

4. T iCN coating :

The flow of the H ₂ ⁺ TiCl. Mixture was maintained for 13 minutes; the methane flow was reduced by half; NL was introduced into the reactor at a rate of 7.13 mi ¹ l / min.

5. TiN coating :

The methane flow was interrupted for 12 minutes and the nitrogen flow rate doubled. With the completion of the TiN coating, both the flow of the H ^ + TiCl ^ mixture and the N ₂ ~ flow were interrupted, the heating elements of the reactor were switched off and the reactor was run through with free H-

blow until it cools to about 250 ° C. At 25O ° C the reactor was purged with nitrogen.

It was found that the insert substrates had a porosity of type A41 to A-2 in their non-enriched Inside, i.e. the material of the main part. One zone enriched with cobalt and one more solid Solution depleted zones extended from the surfaces about 25 µm and 23 µm, respectively, toward the interior. That unenriched interiors had a Rockwell "A" mean hardness of 91.7. The coercive force, Hc, of the substrate was determined to be 186 Oersted.

Example 8

Using the following two step mix and mill procedure were 260 kg of a powder mixture with a Carbon content produced, which was balanced in such a way that a C3 / C4 porosity resulted in:

Level I.

The feed, composed as follows, was milled for 96 hours:

10 108 g TaC (6.08 wt% carbon)

7,321 g NbC (11.28 wt% carbon)

3,987 g TiN

1 100 g C (Molocco Black - a product of Industrial Carbon Corp.)

16 358 g Co

500 g Ethomeen S-15

364 kg 4.8 mm Co-WC Cycloid Naphtha

Stage II
35

The above-mentioned mixture was added to the following added and the resulting mixture grind for a further 12 hours:

il \ I IM /

221.75 kg WC (6.06 wt% carbon) 5.0 kg Sunoco 34 20 naphtha

The finished mixture was then wet sieved, dried

and treated in the hammer mill.
5

Insert blanks were then pressed and subsequently sintered at 1454 ° C. for 30 minutes. This sintering resulted a cobalt enriched zone that covered the main part with a C3 / C4 porosity. The sintered blanks were then ground and honed to the dimensions of the SNG433 inserts, with those with cobalt enriched zone has been removed.

The sintered inserts were then packed into an open graphite canister with flake graphite. This compilation was then at 1371 to 1377 C for one hour under an atmosphere of 25 vol .-% N and 75 vol .-% He hot isostatic at a pressure of 8.76 χ 10 dynes / cm pressed (HIPed). Microstructural testing of a HIPed sample revealed that during hot isostatic pressing a cobalt enriched zone approximately 19.7 µm deep was formed. Also emerged about 4 / U of the surface cobalt and 2, u of the surface “C carbon because of the porosity of type C of the used Substrate.

Example 9

on A mixture of the following materials was used in a Grinding ball mill:

750 , 5 kg 1286 kg 150 , 5 kg 124 kg 152 kg 37 kg

30.0 wt% WC (1.97 µm mean particle size)

51.4 wt% WC (4.43, µm mean particle size)

6.0 wt% Co

5.0% by weight WC-TiC-carbide in solid solution

6.1% by weight TaWC carbide in solid solution
1.5 wt% W

1 «This mixture was put together in such a way that a
Total carbon content of 6.0% by weight was found. These
Materials were 51080 revolutions with 3409 kg
Mill cycloids and 798 1 naphtha. The final particle size was 0.82 µm.

5000 g of the powder was taken from the mixed and

ground approach separated and the amount separated
the following materials were added:

1 »9 wt% TiN {pre-ground to about 96.9 g

1, 4 to 1, 7, um)

0.2 wt% C (Ravin 410) 9.4 g

1500 ml perchlorethylene

These materials were then placed in a tungsten carbide-lined grinding vessel with an inner diameter of
Mill 190 mm with 50% by volume cycloids (17.3 kg) for 16 hours. After the end of the grinding, the portion divided was sieved wet through a 400-mesh sieve,

under a partial vacuum in a Sigma mixing pump b- i
121 ° C ge
given.

Dried at 121 C and placed in a 40 mesh sieve hammer mill

SNG433 blanks were pressed with a force of? 500 kg,

resulting in a bulk density of 8.24 g / cm and a blank height of 5.84 to 6.10 mm.

The blanks were placed on a at 1454 ° C for 30 minutes

JZI I IM /

NbC powder release agent under a vacuum of 10 to 25 Micron sintered and then cooled in the oven. The sintered samples had dimensions of 4.93 x 13.31 χ 13.31 mm, a density of 13.4 g / cm and a total magnetic

«J saturation from 146 to 150 Gauss-cm / g Co. The microstructural Evaluation of the sample pieces showed a continuous porosity of type A and one enriched with cobalt Layer of about 21 µm thick.

The tops and bottoms (cutting faces) of the inserts were then ground down to a total thickness of 4.75 mm. The inserts were then heat treated at 1427 ° C for 60 minutes under a vacuum of 100 microns, to 1204 ° C with a speed

and then chilled in the oven.

cooled to 1204 ° C at a rate of 56 c / h

The flanks of each insert were ground to the size of a square with sides 12.70 mm and the Edges honed to a radius of 0.064 mm.

The inserts were then CVD coated with titanium carbide / alumina using the following method.

The inserts were placed in a coating reactor and heated to about 102 ⁰ 6 to 103o C and kept under a vacuum from 88 to 125 Torr. Hydrogen gas flowed at a rate of 4.73 l / min through a TiCl containing evaporator at 35 to 38 ° C under vacuum. TiCl. Vapor was dragged into the coating reactor with the hydrogen. Simultaneously, hydrogen and methane flowed into the reactor at rates of 19.88 and 2.98 l / min, respectively. These conditions (vacuum, temperature, flow rate) were maintained for 180 minutes, with a firmly adhering TiC coating on the inserts. Then the flow of hydrogen to the evaporator and the flow of methane into the reactor were interrupted. Hydrogen and chlorine were then left in

flow a generator containing aluminum particles at 380 to 400 ⁰ C and 0.5 psi pressure. Hydrogen and chlorine flowed into the generator at rates of 19.88 l / min and 0.8 to 1.0 l / min, respectively. The chlorine reacted with the aluminum to form AlCl., Vapors, which were then fed into the reactor. While hydrogen and AlCl _{3 were flowing into the reactor, CO 2 was also} allowed to flow into the reactor at a rate of 0.5 l / min. These flow velocities were recorded for 180 minutes.

while the inserts were maintained at a temperature of 1026 to 1028 ° C under a vacuum of about 88 torr. This process resulted in a dense coating of Al ₂ O- adhered to an inner coating of TiC.

The evaluation of the coated inserts resulted in the following ' Values:

porosity

Thickness of the cobalt enriched zone (cutting face)

Thickness of the solid solution depleted zone (cutting breast)

Thickness of the coating TiC Al ₂ O ₃

Average Rockwell "A" hardness in the bulk of the substrate

Coercive Force, Hc

A1 in the enriched zone, A1 with occasional B in that Material of the main part

about 39.3 to
up to 43.2

5.9 µm

91.9

170 Oersted

Example 10

or Another 5000 g of the mixture was removed from the original, Approach prepared according to Example 9 separated * Pre-ground TiCN in an amount of 95.4 g (1.9 l'W.-l) and 1.98 g (0.02% by weight) of Ravin 410 carbon black were added to this

3 2 I 1047

Mixture added, mixed for 16 hours, sieved, dried, placed in the hammer mill as in Example 9 described.

Test pieces were pressed into tablets at 1496 ° C Vacuum sintered for 30 minutes and then oven cooled at the rate of cooling of the oven. The evaluation of the sintered pieces produced the following results

Porosity A-1, through and through

Thickness of the cobalt approx. 14.8 µm enriched zone

Thickness of the solid solution up to 19.7 µm impoverished zone

Average Rockwell "A" hardness of 92.4 in the substrate of the main part

Magnetic saturation, 130 Gauss-cm / g Co

Coercive Force (Hc) 230 Oersted

Example 11

A further 5000 g were separated from the original batch prepared according to Example 9. Pre-ground TiCN in an amount of 95.4 g (1.9% by weight) was added, Mixed, sifted, dried, and hammer milled as described in Example 9 for 16 hours Test pieces were then pressed and sintered at 1496 ° C. with the test pieces according to Example 10.

The evaluation of the sintered pieces brought the following results:

Porosity A1, rich in eta phase,

through and through

Thickness of the cobalt approx. 12.5 µm enriched zone '

Thickness of the solid solution up to 16.4 µm impoverished zone

Average Rockwell "A" hardness 92.7 in the main part

Magnetic saturation 120 Gauss-cm / g Co

^ O coercive force, Hc 260 Oersted

Example 12

The following mixture was used using the two-stage milling process described below:

Level I.

The following substances were together with 17.3 kg of

4.8 mm WC-Co cycloids in one lined with WC-Co Given grinding container with an inner diameter of 181 mm and a length of 194 mm. The grinding container was around its cylinder axis with 85 revolutions per

Minute rotates for 48 hours (244800 revolutions): 25

455 G (6.5 Wt .-%) Ni 280 G (4.0 Wt .-%) TaN 112 G (1.6 Wt .-%) TiN 266 G (3.8 Wt .-%) NbN 42.7 G (0.6 Wt .-%) carbon 14.0 G Ethomeen S- 5 1500 ml Perchlorethylene Stage II

The following substances were then added to the meal *. "ViIter and rotates for a further 16 hours (81,600 revolutions):

OZI

ε H-

5890 G (83 , 6 Wt .-%) WC 105 G Sunoco 3420 1000 ml Perchlorethylene

This mixture was balanced in such a way that a binder alloy with 10% by weight of W and 90% by weight of Ni was produced. To when the mixture was removed from the grinding jar it became

sieved moist through a 400-mesh sieve (Tyler), dried at 93 C under a nitrogen atmosphere and ir given a 40 mesh sieve hammer mill.

The samples were pressed into tablets at 1450 ° C. 30 For minutes under a nitrogen atmosphere and one

4 2
Pressure of 6.9 χ 10 dyn / cm sintered and then cooled at the prevailing i furnace cooling rate.

After sintering, the specimens were hot-jisostatic pressed (HIPed) for 60 minutes at 137O ° C in

9 a helium atmosphere at a pressure of 1x10 dynes / cm The optical-metallographic examination of the hot, isostatically pressed samples revealed a porosity of the type

A-3, through and through, and a solid solution depleted zone thickness of about 25.8 µm.

Then the sample was produced again and with the help of the X-ray structure analysis (energy dispersive

x-ray line scan analysis (EDX)) examined at different distances from the cutting breast. Fig. 3 shows a graphical representation of the change in relative nickel, tungsten, titanium and tantalum concentrations as Function of the distance from the cutting face of the pattern.

It can be clearly seen that there is a layer near the surface in which titanium and tantalum coincide with Form tungsten carbide in solid solution carbides are at least partially depleted. This on solid Solution-depleted zone extends approximately 70 .mu.m in the direction of on the inside. The discrepancy between this value and the value reported above is attributed to the fact that the pattern was recreated between the two evaluations, so that during the investigation

■ j different levels within the pattern have been tested.

The depletion of titanium and tantalum is accompanied by a layer enriched with nickel (see FIG. 3). The nickel concentration in the intensified stratum sinks as the distance from the cutting breast decreases from 30 10 to. This shows that the nickel in this zone was partially volatilized during vacuum sintering.

The top of the T ⁱ⁴ -an- and tantalum concentration at 110 is returned to a random large grains or large grains to the scanning, which have a high concentration of these elements.

] 5 The two parallel, horizontal lines show the typical dispersion obtained from analyzing the main part of the sample to get the nominal values of the chemical Properties of the mixture.

20 Example 13

The following mixture was employed using the two-step milling process described below:

Level I.

The following fabrics were made according to Stage I- of the example marry together:

30th example 1 2: (6.4 Weight 455 G (3.9 Weight 280 G (1.6 Weight 112 G (3.7 Weight 266 G (0.9 Weight 35 61.6 G 14th G

h) Ni

I) TaH

2>) TiN

h) NbN

h) C Ravin 410, 502

Ethomeen S-15

2500 ml perchlorethylene

OL II U <4 /

Stage II

Then the following materials were placed in the grinding container and rotated for a further 16 hours:

5980 g (83.6 wt%) WC

140 g Sunoco 3420

The composition of this mixture was chosen so that a binder alloy with 10 wt .-% W and 90 wt .-% Ni originated.

After removing the mixture, it was sieved and dried and ground in the hammer mill according to Example 12.

Pressed test samples were vacuum sintered at 1466 ° C for 30 minutes under a 35 micron atmosphere. The sintered samples had A-3 type porosity, through and through, and up to 13.1 µm thick, on the stronger

Solution impoverished zone.
20th

Example 14

A mixture was made using the following two-step milling process:
25th

Level I.

The following fabrics were lined with WC-Co along with 17.3 kg of 4.8 mm WC-Co cycloids in one Grinding container with an inner diameter of

190 mm and a length of 194 mm. The grinding container was rotated around its axis at 85 revolutions per minute for 48 hours (244 800 revolutions):

177 3 G (2.5 Weight 182 3 G (2.5 Weight 55, G (0.8 Weight 459 G (6.4 Weight 14th G

\) TiHI!>) Carbon 0 Co

Ethomeen S-15 2500 ml perchlorethylene

^ Stage II

The following materials were then placed in the grinding container and rotated for a further 16 hours (81,600 revolutions):

6328 g (87.9 wt%) WC

140 g Sunoco 34 20

The composition of this mixture was chosen so that a binder alloy with 10 wt .-% W and 90 wt .-% Co originated.

After removing the mixture from the grinding container, it was sieved wet through 4OO meshes, dried at 93 C under a nitrogen atmosphere and put in a hammer mill ground through a 40 mesh sieve.

Blanks of inserts were pressed and then sintered at 1468 C for 30 minutes under a vacuum of 35 microns, most of the hydrogen in the samples being volatilized. During the sintering were the pieces are placed on an NbC powder release agent.

The sintered pattern was in the enriched zone A-2 type porosity and A-4 type porosity in the main unenriched part. The pattern had a Rockwell "A" mean hardness of 90.0; a solid solution depleted zone 9.8 µm thick; and a Coercive Force, Hc, of 150 Oersted.

Example 15

A material mixture of the composition corresponding to the mixture described in Example 9 was mixed, ground and pressed into blanks for inserts. the Blanks were then sintered, ground, heat treated and re-ground (only the flank: ^, in exact agreement with the procedure according to the example The heat treatment carried out at the end was

however, a cooling rate of 69 C / h was used.

A use was made by EDX line analysis at various Distances from the cutting breasts of the insert analyzed. The results of this analysis are by the Graph shown in Fig. 2. It shows the existence of a cobalt-enriched layer that differs from the Cutting breasts at a depth of about 25 µm, extending into the interior and to which a layer of Cobalt adjoins partially depleted material, which is about 90 in order from the cutting breasts into the interior extends. Although not shown in Fig. 2, there was partial solid solution depletion in that with cobalt enriched layer found, while an accumulation of solid solution in the partial cobalt impoverished layer was found.

The two horizontal lines show the typical spread around the nominal values of the chemical properties of the mixture, which occurs when analyzing the material of the main part.

The above description and the detailed examples serve to illustrate some of the possible Alloys, products, processes and uses falling within the scope of the invention such as he is defined by the following claims.

,, Yr. Blank page

Claims (1)

Patent Attorneys · European Patent Attorneys ---,; - Munich Stuttgart KENNAMETAL INC. March 24, 198 P.O. Box 231 Latrobe, Pennsylvania 15650 /V.St.A. Our reference: K 1102 Claims 1. A cemented carbide body containing a first Carbide, a metallic binding alloy, a solid solution of the first carbide and a second carbide, a layer with a binder enrichment close to one outer surface, the body having a porosity essentially of type A to B through and through having. ² Cemented carbide body containing a first carbide, a metallic binding alloy, a solid solution of the first carbide and a second carbide, an at least partially solid solution depleted layer near an outer surface of the body, and with one throughout the body present porosity essentially of type A to B. 3. Cemented carbide body containing a first carbide, a metallic binding alloy, a transition metal as a second carbide, the free formation of which argie at a temperature above the melting point of the Binding alloy is more negative than that of the first carbide, with the second carbide being in the form of a solid solution is present with the first carbide, and with a layer that near an outer surface of the body a Has binder enrichment, with the body through and through a Poros.i did essentially predominantly type A to B owns. J 4. Cemented carbide body according to one of the claims 1, 2 or 3, characterized in that it also contains nitrogen in the form of a carbonitride in a contains solid solution of the first and second carbides. 5. cemented carbide body containing tungsten carbide, a metallic binder, a carbonitride in the form of a solid solution with tungsten and with one from the group of transition metals of the IV. and V subgroups of the periodic table (groups IV B and V B) selected metal, and a layer of material near an outer surface of the Body that is at least partially depleted of the carbonitride present in the form of a solid solution is. 6. cemented carbide body according to claim 5, characterized in that it is in the form of a solid solution present carbonitride is a tungsten-titanium-carbonitride. 7. cemented carbide body containing tungsten carbide, specify one metallic binder, one with binding metal ^iJ enriched layer near an outer surface of the body, the body having a porosity essentially of type A through B through and through. 8. cemented carbide body containing tungsten carbide, a metallic binder, one selected from the group of the carbides of the IV B and V B transition metals Metal carbide, the body having a porosity through and through essentially of type A to B having and wherein the metal carbide together with the tungsten carbide form a carbide in the form of a solid solution, as well as with at least one partially depleted of the carbide in the form of a solid solution near one outer surface of the body. 9. cemented carbide body according to one of claims 5, 6, 7 or 8, characterized in that the Binder is selected from the group consisting of cobalt / nickel, iron and their alloys. 10. Cemented carbide body containing tungsten carbide, a cobalt binder alloy, a binder metal enriched '"' layer near an outer surface of the body, the cobalt binder alloy having an overall level of magnetic saturation of less than 158 Gauss-cm / g cobalt. ■ J5 11. Cemented carbide body according to claim 10, characterized in that characterized in that the cobalt binder alloy has a total magnetic saturation value of about 145 to 157 Gauss-cm / g cobalt. 12. Cemented carbide body according to claim 10, characterized characterized in that the cobalt binder alloy has an overall magnetic saturation value of less 3
than 126 Gauss-cm / g cobalt. 13. Cemented carbide body containing tungsten carbide, a cobalt binding alloy, one selected from the group of the carbides of the IV B and V B transition metals Metal carbide, which together with the tungsten carbide is a solid solution Carbide forms, an at least partially solid solution depleted layer near an outer one Surface of the body, the cobalt binder alloy having a total value of magnetic saturation of less than 158 Gauss-cm / g cobalt. 14. Cemented carbide body according to claim 1J>, characterized characterized that the cobalt binding alloy a Total magnetic saturation value of about 145 to 157 Gaussian cm ³ / g cobalt. 15. Cemented carbide body according to claim 13, characterized characterized in that the cobalt binder alloy has an overall magnetic saturation value of less than 126 Gauss-cm / g cobalt. 16. Cemented carbide body containing tungsten carbide, cobalt, one from the group of carbides of IV B and V B transition metals selected metal carbide, a cobalt enriched layer near an outer surface of the body, the body being through and by a porosity, essentially of type A to B. 17. Cemented carbide body according to claim 16, characterized in that the content of the transition metal carbide is at least partially depleted in the layer enriched with cobalt. 18. cemented carbide body according to claim 16 or 17, characterized in that the metal carbide is selected from the group consisting of titanium, hafnium, tantalum and niobium Group is selected. 19. Cemented carbide body according to claim 16 or 17, characterized in that the content of metal carbide is at least 0.5% by weight. 20. Cemented carbide body according to claim 18, characterized in that the content of metal carbide is at least Is 0.5% by weight. 21. Cemented carbide body according to claim 16 or 17, ^OsJ, characterized in that the layer enriched with cobalt on the outer surface has a cobalt content of 1.5 to 3 times the mean cobalt content of the body. 22. Cemented carbide body according to claim 16, characterized in that the enriched with cobalt
Layer extends from the outer surface of the body towards the interior to a minimum depth of 6 µm. 23. Cemented carbide body according to claim 21, characterized in that the enriched with cobalt
Layer extends from the outer surface of the body towards the interior to a minimum depth of 6 µm. 24. Cemented carbide body according to claim 22, characterized in that the enriched with cobalt Stratify from the outer surface of the body towards the inside to a depth of
Stretches from 12 to 50 µm. 25. Cemented carbide body according to claim 23, characterized in that the enriched with cobalt Stratify from the outer surface of the body towards the inside to a depth of
Stretches from 12 to 50 µm. 26. Cemented carbide body according to one of the claims 1, 3, 7, 16 or 24, characterized in that the outer surface of the body comprises a cutting face, the cutting face adjoins a lateral boundary surface (flank), that a cutting edge is located at the point where the cutting face and the flank meet and that the enriched layer extends from the cutting breast in the direction of the
Interior extends. 27. Cemented carbide body according to claim 26, characterized in that it additionally has a ht
has dense, high-melting-point coating that is attached to
the outer surface of the body is bound and consists of one or more layers. 28. Cemented carbide body according to claim 27, characterized characterized in that the material from which the layer or layers of the coating is constructed or are made from the carbides, nitrides, borides and carbonitrides of titanium, zirconium, hafnium, Niobium, tantalum and vanadium and the group consisting of the oxide and oxynitride of aluminum is. 29. Cemented carbide body according to claim 27, characterized in that the coating consists of a layer Contains titanium carbide. 30. Cemented carbide body according to claim 27, characterized in that the coating consists of a layer Contains titanium carbonitride. 31. Cemented carbide body according to claim 27, characterized in that the coating consists of a layer Contains titanium carbide and a layer of titanium nitride. 32. Cemented carbide body according to claim 31, characterized in that the coating also has a Contains a layer of titanium carbonitride. 33. Cemented carbide body according to claim 27, characterized in that the coating consists of a layer Contains aluminum oxide. 34. Cemented carbide body according to claim 33, characterized in that the coating also has a Contains a layer of titanium carbide. 35 35. Cemented carbide body according to one of claims 1, 3, 5, 6, 7 or 10, characterized in that he also has a hard, dense, high-melting point -i- has coating that is attached to the outer surface of the Body is bound and consists of one or more layers. 36. Product which is produced by a process in which a binder-enriched layer is formed near an outer surface of a cemented carbide body, specifically by the fact that a compact of a first carbide, a binding alloy ur. ' ¹ produces a chemical agent with an essentially even distribution of these substances, the chemical agent consisting of that of the transition metals, the carbides of which have a free energy of formation at a temperature above the melting point of the binding alloy, which is more negative than that of the first Carbides, as well as the group consisting of their alloys, hydrides, nitrides and carbonitrides, and in which the compact is compacted, the chemical agent is at least partially converted into a carbide by heat treatment and the content of binding alloy increases in the direction of the outer surface and so forms the enriched layer. 37. Product made by a process in which a binder-enriched layer is formed near an outer surface of a cemented carbide body, in which a compact of tungsten carbide, a binder alloy and a chemical agent with a substantially smooth distribution of these substances manufactures, whereby the chemical agent from the transition metals, whose carbides at a temperature which is above the eutectic temperature of the binding , have a free energy of formation which is more negative than that of tungsten carbide, as well as from their alloys, hydrides, Nitriden and Carbonxcriden consisting group is selected in which the 32.1 ID. 4th Compact is compacted, the chemical agent by heat treatment at least partially in a carbide is transferred and the content of binder metal increases towards the outer surface and so the enriched layer is formed. 38.Product that is manufactured using a process wherein a binder enriched layer near an outer surface of a cemented carbide body is formed with a porosity essentially of type A to B, in which a first carbide powder, a binder alloy powder and a powdery chemical agent are ground together and mixed, the chemical agent from the IV B and V B transition metals as well as their Alloys, hydrides, nitrides and carbonitrides consisting of a group is selected in which one The compact is pressed out of the powders and at a temperature above the melting temperature of the binding alloy sinters. 39. Product according to one of claims 36, 37 or 38, which is produced by a method in which in addition, the layer enriched with binder is removed from selected areas of the product. 40. Product according to claim 39, which by a method is made, in which, in addition, a firmly adhering, hard, wear-resistant, refractory coating is deposited with one or more layers. 41. The product of claim 40, wherein the material from which each of the coating layers is made is of the from the carbides, nitrides and carbonitrides of titanium, zirconium, hafnium, niobium, tantalum and vanadium and is selected from the group consisting of the oxide and oxynitride of aluminum. ] 42. The product of claim 38, wherein the first carbide powder Contains tungsten carbide. 43. Product according to claim 37, characterized in that c that the compact is also essentially more uniform Distribution contains a second carbide, selected from that of the IV B and V B transition metal carbides and their solid solutions consisting of the group is selected, and that the product by a process IQ manufactured in which this carbide is in one of the direction away from the outer surface. 44. Product according to claim 42, characterized in that the binder is selected from that of cobalt, nickel, iron and whose alloys existing group is selected. 45. A method for producing the cemented carbide body according to any one of the preceding claims, forming a binder-enriched layer near an outer surface of the cemented carbide body, characterized in that a compact from a first carbide, a binder metal and a chemical agent is produced with a substantially uniform distribution of these substances, the chemical means made from transition metals, whose carbides are at an above the binder-carbon eutectic lying temperature have a free energy of formation that is more negative than that of the errten Carbides, as well as their alloys, Hydric ": n, nitrides and carbonitrides selected group is that the compact compacts the chemical agent by heat treatment at least partially converted into a solid solution with the first ■ "" »■» "bid and that the binder content near the outer surface is increased during the heat treatment. -ΙΟΙ 46. process for the production of cemented carbide bodies according to one of claims 1 to 44, characterized in that one enriched with cobalt binder Layer near an outer surface of the cemented carbide body with a porosity substantially Type A is made by grinding and mixing powders, the tungsten carbide, cobalt and one of the hydrides, nitrides, and carbonitrides of the IV B and V B transition metals existing group contains selected metal compound by pressing a compact therefrom Powders and by sintering the compact at a temperature above the melting point of the binder. '5 47. The method according to claim 45 or 46, characterized in that that the binder-enriched layer from selected areas of the outer surface Will get removed. * ® 48. Method according to claim 45 or 46, characterized in that a firmly adhering, hard, wear-resistant coating is additionally deposited on the outer surface, which consists of one or more layers, the material of which ^J these layers are made, is selected from the group consisting of the carbides, nitrides, borides and carbonitrides of group consisting of the oxide and the oxynitride of aluminum group of titanium, zirconium, hafnium, niobium, tantalum and vanadium as well. 30th 49. The method according to claim 46, characterized in that the powder additionally contains a second carbide powder which consist of the carbides of IV B- and V B-Metallo and their solid solutions the group is selected. ■ j 50. The method according to claim 45, characterized in that that the compacted compact also has a second carbide powder in a substantially uniform distribution contains that from the IV B and V B metal carbides and their fixed solutions existing group is selected, and in addition this second carbide is spread and scattered in a direction away from the outer surface. ] Q 51. Method n ^ h claim 46, characterized in that that during sintering a group selected from the group consisting of hydrogen and nitrogen Element is at least partially volatilized. 52. The method according to claim 47, characterized in that free carbon during grinding and mixing is added in an amount sufficient to contain a tungsten-cobalt binder in the sintered compact low tungsten content. 53. Cemented carbide body containing a first carbide, binder metal alloy and a partial binder depleted layer below but separate from an outer surface of the body. 25th 54. Cemented carb .dkörper according to claim 53, characterized characterized in that the first carbide contains tungsten carbide, that the metallic binder contains cobalt and that the body further has a layer partially depleted in cobalt below the enriched layer contains. 55. Cemented carbide body containing a first carbide, a binder metal alloy, a solid solution from the first carbide and a second carbide ,, one first layer enriched with solid solution underneath but separated from an outer surface of the body. 56. Cemented carbide body according to claim 55, characterized characterized in that the first carbide contains tungsten carbide, that the metallic binder contains cobalt, that the second carbide in the solution is selected from the group of carbides of the IV B and V B elements and that the body additionally has a layer that is at least partially depleted of the solid solution between the outer surface and the first layer having.
10 57. cemented carbide body containing tungsten carbide, Cobalt, a solid solution of tungsten carbide and a second carbide, which is made up of the carbides of the IV B and V B elements consisting group is selected, as well as one enriched with cobalt, at least first layer partially depleted of the solid solution, this layer being located near an outer surface of the body is located, and a second, partially depleted in cobalt and with the solid solution ^ζυ enriched layer, which is below the first layer. 58. Cemented carbide body according to claim 53, 54, 55, 56 or 57, characterized in that it additionally has a hard, dense, high-melting coating which is bonded to the outer surface of the body and has one or more layers. 59. Cemented carbide body according to claim 58, characterized characterized in that the coating contains a layer of titanium carbide. 60. Cemented carbide body according to claim 58, characterized characterized in that the coating consists of a layer Contains titanium carbonitride. 61. Cemented carbide body according to claim 58, characterized in that the coating consists of a layer Contains titanium nitride. 62. Cemented carbide body according to claim 58, characterized in that the coating consists of a layer Contains aluminum oxide.