RU2250810C1 - Coated cutting tool - Google Patents

Abstract

FIELD: application of coatings, namely by evaporation and condensation in vacuum, possibly manufacture of cutting tools with wear resistant coatings.

SUBSTANCE: cutting tool includes base of tool and wear resistant ion-plasma coating applied onto it. Coating includes silicon and it is made of titanium nitride and silicon at relation of those components, mass %: titanium, 98.8 -99.1; silicon, 0.9 - 1.2.

EFFECT: enhanced strength of tool.

1 dwg, 1 tbl

Description

The invention relates to the field of coating, in particular to coating by evaporation and condensation in vacuum, and can be used in tool production to obtain wear-resistant coatings on a cutting tool.

Known cutting tool with a wear-resistant ion-plasma coating TiN with a thickness of 3-8 μm (see Vereshchak A.S. The performance of the cutting tool with wear-resistant coatings. M: Mechanical Engineering, 1993. S. 252).

The reasons that impede the achievement of the technical result indicated below when using the known coated cutting tool include the fact that in the known coated cutting tool, the applied coating has insufficient microhardness and adhesion to the tool base and high residual stresses, which leads to a decrease in the resistance of the cutting tool during its operation.

The closest cutting tool with a coating of the same purpose to the claimed invention in terms of features is a cutting tool with a coating containing a tool base and a wear-resistant ion-plasma coating of titanium and zirconium nitride (see Tabakov V.P., Ezersky V.I., Polyanskov Yu.V. Improving the operability of a cutting tool by means of a directed change in the composition of a wear-resistant coating // Vestnik mashinostroeniya. 1989. No. 12. P.45), adopted as a prototype.

The reasons that impede the achievement of the technical result indicated below when using a known cutting tool with a coating adopted as a prototype include the fact that a known cutting tool with a coating does not provide sufficient adhesion of the coating to the tool base and microhardness of the coating and low residual stresses, as a result which decreases the resistance of the cutting tool during its operation.

The invention consists in the following. A wear-resistant coating of titanium nitride and silicon is applied to the tool base with a ratio of titanium and silicon, wt. %: titanium 98.8-99.1, silicon 0.9-1.2.

The technical result is an increase in the resistance of the cutting tool.

The specified technical result in the implementation of the invention is achieved by the fact that the known coated cutting tool contains a tool base and a wear-resistant ion-plasma coating of titanium nitride and silicon applied to it.

The peculiarity lies in the fact that the coating contains silicon and is made of titanium nitride and silicon with a ratio of titanium and silicon, wt.%: Titanium 98.8-99.1, silicon 0.9-1.2.

The application of a coating made of titanium nitride and silicon at a ratio of titanium and silicon, wt.%: Titanium 98.8-99.1, silicon 0.9-1.2, leads to a decrease in stresses in the coating, to an increase in microhardness and adhesion strength with an instrumental basis and, as a consequence, to increase the resistance of the cutting tool during its operation.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information and identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find a source characterized by features identical to all the essential features of the claimed invention, determined from the list of identified analogues of the prototype, as the closest in the totality of the features of the analogue, allowed us to establish a set of essential in relation to the Riva applicant technical result in the claimed hallmarks coated cutting tool as set out in the claims.

Therefore, the claimed invention meets the condition of "novelty."

To verify the compliance of the claimed invention with the condition "inventive step", the applicant conducted an additional search for known solutions in order to identify signs that match the distinctive features of the claimed cutting tool with a coating. The search results showed that the claimed invention does not follow explicitly from the prior art for a specialist, since the influence of the transformations provided for by the essential features of the claimed invention on the achievement of a technical result is not revealed from the prior art as defined by the applicant, in particular, the following transformations are not provided for by the claimed invention:

- addition of a known product by any known part (s) attached to it (by) according to known rules, in order to achieve a technical result in respect of which the effect of such an addition is established;

- replacement of any part (s) of a known product with another known part to achieve a technical result, in respect of which the influence of such a replacement is established;

- the exclusion of any part (element) of the product with the simultaneous exclusion of the function due to its presence and the achievement of the usual result for such exclusion (simplification, reduction of weight, dimensions, material consumption, increased reliability, reduced process time, etc.);

- an increase in the number of elements of the same type, actions to enhance the technical result, due to the presence in the tool of just such elements, actions;

- the implementation of a known tool or part (s) of a known material to achieve a technical result due to the known properties of this material;

- the creation of a tool consisting of known parts, the choice of which and the relationship between them are based on known rules, recommendations, and the technical result achieved in this case is due only to the known properties of the parts of this tool and the relationships between them.

The described invention is not based on a change in a quantitative characteristic (s), the presentation of such signs in relationship, or a change in its appearance. This refers to the case when the fact of the influence of each of these characteristics on the technical result is known, and new values of these signs or their relationship could be obtained on the basis of known dependencies and patterns.

Therefore, the claimed invention meets the condition of "inventive step".

Information confirming the possibility of carrying out the invention with obtaining the above technical result

The invention is illustrated by the drawing, which shows a cutting tool with a coating.

The coated cutting tool comprises a tool base 1 and a coating 2 applied thereon, made of titanium nitride and silicon.

Coatings were applied as follows.

The coatings were applied by the CIB method (condensation from the plasma phase in vacuum with ion bombardment). Non-grind plates preliminarily cleaned of contaminants made of MK8 hard alloy and P6M5K5 high-speed steel were placed in the chamber of the Bulat-6T installation with electric arc evaporators installed in it, the cathode materials of which include coating elements.

An arc discharge was ignited in the space between the plates and the cathode to vaporize the cathode material, nitrogen was supplied to the chamber to interact with the vaporized cathode material. A coating of titanium nitride and silicon (Ti, Si) N with a thickness of 5 μm was condensed. After that, the nitrogen supply to the chamber was stopped, the arc discharge was turned off. Wear-resistant plates were cooled in a chamber to room temperature.

Residual stresses in the coating were determined on a DRON-3 X-ray diffractometer.

The microhardness of the coating was measured on a PMT - 3 microhardness tester.

Durable tests of the cutting tool were carried out with the longitudinal turning of billets made of 30KhGSA steel on a 16K20 lathe. Cutting conditions for a tool with inserts made of MK8 carbide: cutting speed V = 180 m / min, feed S = 0.15 mm / rev, cutting depth t = 0.5 mm, processing was performed without the use of coolant; for tools with plates made of R6M5K5 high-speed steel: cutting speed V = 55 m / min, feed S = 0.3 mm / rev, cutting depth t = 0.75 mm, processing was performed using coolant (5% water emulsol solution Ukrinol-1M).

For the wear criterion, the value of the chamfer of wear on the rear surface was taken: h _З = 0.4 mm for plates made of MK8 hard alloy and h _З = 0.6 mm for plates made of R6M5K5 high-speed steel. The effectiveness of the tool was determined by the value of the coefficient of increase in resistance, defined as the ratio of the tool life with a coating (Ti, Si) N to tool life with a coating (Ti, Zr) N.

The value of residual stresses, peeling coefficient, microhardness of coatings (Ti, Zr) N and (Ti, Si) N and the resistance of the cutting tool with these coatings are shown in the table.

The composition of the coating, wt.% (Ratio of components) Microhardness Нμ, GPa Peeling ratio Residual stresses σ ₀ , MPa Resistance T, min Ti Zr Si MK8 90 10 - 31.5 1.76 2147 32 99.33 - 0.67 36.1 1.38 1629 45 99.00 - 1.00 37,4 1.43 1812 51 98.67 - 1.33 38,2 1.49 1923 48 R6M5K5 90 10 - 28.0 0.86 3870 56 99.33 - 0.67 30.1 0.50 2433 76 99.00 - 1.00 31.9 0.54 2634 84 98.67 - 1.33 32.6 0.57 2737 79

As can be seen from the table, the presence of silicon titanium nitride in the coating reduces the residual stresses in the coating, increases the microhardness and adhesion of the coating to the tool base (as evidenced by a decrease in the peeling coefficient), and increases the resistance of the cutting tool with the (Ti, Si) N coating by Compared to coated tools (Ti, Zr) N.

The resistance of a cutting tool with a coating (Ti, Si) N compared to a tool with a coating (Ti, Zr) N is increased 1.5 times for a tool with inserts made of P6M5K5 high-speed steel, and 1.6 times for a tool with inserts made of hard alloy MK8.

Thus, the above information indicates that when using the claimed cutting tool coated with the following set of conditions:

- a tool embodying the claimed cutting tool with a coating in its implementation, is intended for use in industry, namely in the field of coating, in particular in the field of coating by evaporation and condensation in vacuum, and can be used in tool production to obtain wear-resistant coatings on cutting tool;

- for the declared cutting tool with a coating in the form as described in the independent clause of the claims, the possibility of its implementation using the means and methods described in the application or known prior to the priority date is confirmed;

- a tool embodying the claimed invention in its implementation, is able to ensure the achievement of the perceived by the applicant technical result.

Therefore, the claimed invention meets the condition of "industrial applicability".

Claims (1)

A coated cutting tool containing a tool base and a wear-resistant ion-plasma coating deposited on it, characterized in that the coating contains silicon and is made of titanium and silicon nitride at a ratio of titanium and silicon, wt.%: Titanium 98.8-99.1, silicon 0.9-1.2.