DE2018662A1 - Composite material for cutting tools - Google Patents

Description

DR.-INQ. UlP -.- l ^ a. M. «Ο. ΟΙβ ^ .- ΡΗΥβ. DR. DIPI..PHY ». HÖGER-STELLRECHT-GRIESSBACH-HAECKER PATENT LAWYERS IN STUTTGART

■ λ 38 112 b 2018662

April 13, 197o

Laboratoire Suisse de Recherches

Horlogeres,
Rue Breguet 2, Neuchatel (Switzerland)

Composite material for cutting tools

009860/1398

_V i.

Those used today for machining Cutting materials represent a compromise between their wear resistance and their toughness. For example, the extremely wear-resistant diamond is very brittle and therefore only finds use in special cases. The high-speed steel, which is still widely used today, is relatively tough, but not very wear-resistant.

It is now conceivable to use a tough material with a hard, wear-resistant layer to cover, thereby creating an ideal To obtain cutting material that is both tough and wear-resistant is.

For such abrasion-resistant layers, a number of metallic and non-metallic hard materials are embossed, such as carbides, borides, nitrides and suicides of the transition metals of groups K to 6 of the periodic table, diamond, corundum, hard minerals, boron carbide, silicon carbide, cub. Boron nitride and aluminum nitride. In compact form, these substances are extremely brittle. However, some of them can be deposited as thin layers on suitable carrier materials (substrates) and in this form can be very ductile. An example is the T + tank carbide coating of steel by thermochemical deposition from the Qas phase. A simple combination of a tough substrate with a very hard, only a few inches thick hard material layer, however, due to the widely differing properties of the layer and substrate material, leads to a material that does not meet the high requirements placed on a cutting material. ■ ■

It has now been found that if at least one intermediate layer with very specific properties is provided between the tough substrate and the hard cover layer, a composite material for cutting tools can be obtained that has a multiple of the wear resistance of the hardest hard metals and also has a flexural strength of, for example more than 200 kg / mm ² the toughness of the commercially available SinUrhartot balls is reached or partly exceeded.

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The composite material according to the invention is marked by a metallic or non-metallic substrate, at least one intermediate layer and a wear-resistant cover layer, the intermediate layer having the following properties

a) their hardness lies between that of the substrate and that of the top layer,

b) it is more ductile than the top layer,

c) their coefficient of thermal expansion is between that of the substrate and that of the top layer,

d) it is partially dissolved both in the substrate and in the top layer,

e) their melting point is higher than that for application temperatures necessary for the surface layer,

The mean grain size is much smaller than the layer thickness.

So comes the intermediate layer and its properties the essential importance of the present invention. Thanks to the The properties mentioned above are coordinated in such a way that a gradual transition between substrate and top layer is ensured is. .

The finer the gradation between several intermediate layers is, the better the substrate and top layer can be combined with one another associate. Often, however, one or two intermediate layers are sufficient. This is especially true for diffusion layers.

One can expediently produce, for example, a carbide-containing top layer and use optionally substituted aliphatic, aromatic, cycloaliphatic or heterocyclic hydrocarbons as the carbon source. Nethane or dioyclopentadiene, for example, are very suitable.
Examples

1. Chromium steel, made from ledeburitis, is in the form of square sonic plates. Br is packed in a powder mixture consisting of an inert ceramic Wet, chromium and Ammoniumohlorid and aufceheizt to 90O ⁰ C. Eb forms of chromium chloride, which transported over the Oasphase and at the top

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surface of the steel parts is decomposed. The deposited chromium is partially diffused into the surface and forms, together with the carbon of the base material, a 5 .mu.m thick "hard" layer enriched with carbon halides. The overlying chromium is 1 to 2 / µm. The parts treated in this way are coated in an Oae-Gemisoh of 96 VolI * H ₂ + 2 VolI * CH ^ ♦ 2 VolI * TiCl ₄ at 900 ° C and a pressure of 20 Torr with a 6 µm thick TiC-sole. Here a transition zone is formed in which the chromium is partially converted into chromium by diffusion of the carbon. The so-remunerated Sohneldeplättohen can be used without post-processing. With fine turning of brass MS 58 and 1 * C-steel 5-to-20-fold increases in service life are achieved.

2. Sin Hartmetailachneldeplättohen consisting of the carbides WC "TiC" NbC or VC and Co as a binder is in a Oas "gemlsoh 97 VoI * IL, + <- heated VoI * CH ₄ + 1 * VoI CrCu at 102O ⁰ C. After a chromium + chromium carbide layer 1 to 2 μm thick has been deposited, 2% TiCl ^ are added to the Qa * and the pressure is reduced to 10 Torr. After h h a 3 to 4 micron thick "weak ohroracarbidhaltlge Tltankarbldeohloht has formed. This is harder than pure titanium carbide. Through the use of the mouse, it was possible to increase the hardness of the original hard metal surface by forming ternary alloys of the W ₅ Co ₃ C type with the carbides.

When turning against a steel, the material no. QiOCWl was treated with the untreated hard metal plates after 12 minutes Abrasion of 0 «2 mm and thus the upper limit of the susceptible insole achieved. On a remunerated platoon, however, was under smooth cutting conditions after 30 am an abrasion of only 0.005 bsi detected.

Further Example® for Kooblnatlomn, which by suitable « ZwlaohensohJ ^, similar to "bring quality enhancements"

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S-

matrix Intermediate layers Fe-Silicides
-. Top layer NIMONIC
(e.g. 80 % Nl +
20 % Cr) T
t Ni, Al j NiAl
¹ y ZrB ₂ STELLITE
(e.g. 20JiCr, 15 # W,
5i # Co, approx. 10 # Nl,
1.4 % Mn, 1.7JiPe) -
Cr carbides ZrC Cr-Mo-C steel
with 33 % TiC
"I. i
I Mo j MbC B ₄ C Steel air supply j B
ι TiB ₂ High speed steel j
S 10-4-3-ok ok ZrB ₂ Cermet
(Cr boride with!
Cr-Mo binder) B ₄ C

Example 9

A cutting tip consisting essentially of Al ₂ C and Ni as a binder is heated to 900 ° C. in hydrogen. After adding 0.5 % by volume of CrCl and 0.2 % by volume of dicyclopentadiene in the gaseous state, the total pressure is reduced to 15 Torr. NaOH for 30 min the temperature to 850 ⁰ C is added as a further lowered and Realttlonsgas 2% by volume of TiCl _4. After a further 60 minutes, the reaction gases are replaced by argon and the sample is cooled to room temperature. On the cutting tip has a 1 to 2 pm dioke Chromkarbldsohioht formed thereon and an 8 to 10 micron thick doped chromium carbide Tltankarbidsohloht.

When machining cast steel, the naoh pointed out the described Process produced composite material 6 to 10 times the service life of that usually used for cast steel

Sohneldaaterlallen on.

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2018 G 6 2

According to the invention, the following advantages can be obtained will:

- High toughness with low insole, therefore higher Stand tents of the toolsj higher cutting speeds associated with production branch.

- Possibilities for the use of partly cheap and easy to work substrate materials with high toughness, which are still used today as cutting materials because of their lack of resistance to cracking out of the question, like almost all hardenable steels, various nickel-. Copper, titanium, cobalt and aluminum

P alloys, hard metal grades, which in son · attempt as to Proven to be soft, ceramic sintered materials with a large proportion of binder.

- Improvements in the reconciliation resistance of the commercial ones Cutting materials un 2 to 20 times while maintaining their toughness.

- Materials that are very difficult to work with are replaced by the material to be machined Design accessible.

The accompanying drawing shows the dependence of hardness on flexural strength for various cutting materials. _ The · bending strength has a significant influence on the toughness ™ ; the hardness is closely related to the insole resistance of the material. Area A relates to known sehneldmaterlallen, such as special hard metals 1, cutting ceramics 2, sintered carbide · jj and Sohnell lathe tools 4. Area B relates to the new composite materials.

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Claims (1)

2 01 8 β 6 2 1. Composite material for sons tools, characterized by a metallic or non-metallic substrate "at least" an intermediate layer and a wear-resistant top layer, the intermediate layer having the following properties: a) their hardness is between that of the substrate and that of the top layer » b) it is more ductile than the top layer " c) their coefficient of thermal expansion is between that of the substrate and that of the top layer, d) it is both la substrate and in the top layer partially solved, e) is their melting point. higher than that to «muster temperatures necessary for the surface layer, f) the mean grain size is much smaller than the layer thickness. 2. Material according to claim 1, characterized by a Substrate made of chrome steel, an intermediate layer Chromium and a top layer of titanium carbide, being in the one another Adjacent areas of the substrate, the intermediate layer and the top layer contain chromo carbide. 3. Material according to claim 1, characterized by a Substrate made of tungsten, titanium, niobium and / or vanadium carbide with a cobalt binder, an intermediate layer made of chromium and a cover layer made of titanium carbide, in the adjoining areas of the substrate, the intermediate layer and the cover layer Chromoarbide is included. A. Material according to claim 1, characterized by a substrate made of an alloy of 80 % Ni and 20 % Cr, a first intermediate layer made of Ni, Al, a second intermediate layer made of NiAl and a cover layer made of ₂ 5. Material according to claim 1, characterized by a substrate made of 20 % Cr, 15 % W, 51 % Co, approx. 10 % Nl ₄ 1.4 % Mn, 1.7 * Fe, tine intermediate layer made of chromium blades and one 009850/1398 2018R62 Deoxohioht "from zirconium carbide. 6. Material naoh Anapruoh 1, characterized by a substrate made of hardenable steel with up to 50 % TiC, a first intermediate layer made of molybdenum, a second intermediate layer made of molybdenum carbide and a top layer made of boron carbide of the formula B ^ C. 7. Material naoh claim 1 «characterized by a substrate made of an air-hardening steel, an intermediate layer made of boron and a top layer made of titanium boride of the formula TiB ₂ * 8. Material naoh claim 1, characterized duroh a substrate made of a sonic turning steel, an intermediate layer made of bisensilloids and a deoxa made of Zlrkonborid of the formula ZrB ₂ . 9. Material naoh claim 1, characterized duroh a substrate made of a Metallkeramisohen Cr boride with Cr-Mo binder, an intermediate layer of zirconium boride of the formula ZrBg and one Top layer made of boron carbide of the formula B ^ C. 10. Material naoh claim 1 «characterized duroh a substrate made of an adhesive steel with up to 50 % TiC, an intermediate layer of chromium and a Deoksohloht made of titanium carbide, wherein in the adjoining Berelohen of the substrate, the intermediate layer and the Deoksohioht chromoarbide is included. 11. Process for the production of a composite material naoh the claims 1-10, characterized in that the Zwlsohensohlohtmaterlal duroh chemical reaction on the substrate the gas phase is deposited, whereby substrate material and Zwleohensohlohtmaterial diffuse into each other, and that one deokaohioht duroh chemical reaction from the Qaephase on the Interlayer deposited, with cover layer material and Diffuse evenly into one another. 12. The method according to claim 11, characterized in that that «Ine carbide-containing top layer is produced and thereby as Carbon source optionally substituted eliphatic, aromatic, cycloaliphatic or heterocyclic hydrocarbons used. 009850/1398 15. The method according to claim 12, characterized in / that methane is used as a carbon source. 14. The method according to claim 12, characterized in that « that dicyclopentadiene is used as a carbon source. 15. The method according to claim 11, for the preparation of the material according to claim 2, characterized in 'that Sehneideplättchen from ledeburitic chrome steel in a powder mixture of an inert ceramic material, chromium and ammonium chloride appeared, the mixture heated to 900 ⁰ C, whereby gaseous Chromohlorid to the surface of the platelets is decomposed and a chromium layer is formed, which partially diffuses into the platelet surface and contains chromium carbide, and that this intermediate layer can be obtained by reaction in the gas phase with a mixture of hydrogen, methane and TiCl ^ at 90O ⁰ C and 20 Torr Titanium carbide Coating, whereby chromium and titanium carbide partially diffuse into one another and chromium carbide is formed. 16. The method according to claim 11, for the production of the material naoh claim 3, characterized in that a substrate made of tungsten, titanium, niobium or vanadium carbide with a cobalt binder by reaction with a gas mixture of hydrogen, methane and CrCl, at 1020 ⁰ C bit is coated with a chromium layer, with chromium partially diffusing into the substrate surface and forming chromium carbide, and then the CrCl. partially replaced by TiCl ^ and forms a titanium carbide layer doped with chromium carbide on the intermediate layer at 20 Torr. 17. The method according to claim 11, for the production of a material according to claim 10, characterized in that a cutting tip, which consists essentially of Al ₂ O, with Ni as a binder, is ^{heated in hydrogen to 90O 0} C, after addition of gaseous CrCl , and dioyolopentadiene reduces the Druok to about 16 Torr and deposits chroacarbide as an intermediate layer, and then, after adding gaseous "TiCl4", forms an old chroaoarbide-doped top layer of titanium carbide. 009850/1398 Blank page